Had a test game against Daves Hive Fleet Undercoat last night, though I forgot my camera so I am going from memory! My list was slightly over 1,500 by 11 points so Dave added a Genestealer to even it out incase any of you add up things and point out totals are wrong
Grey Knights - 1,500 points
HQ
Ordo Xenos Inquisitor - power sword, power armour & rad grenades
Elite
Purifier Squad w/ Rhino - 2 x psycannons, 2 x nemesis halberds & nemesis daemon hammer
Purifier Squad w/ Rhino - 2 x psycannons, 2 x nemesis halberds & nemesis daemon hammer
Troops
Strike Squad w/ Rhino - psycannon & daemon hammer
Strike Squad w/ Rhino - psycannon & daemon hammer
Strike Squad w/ Rhino - psycannon & daemon hammer
Strike Squad w/ Rhino - psycannon & daemon hammer
Strike Squad w/ Rhino - psycannon & daemon hammer
Heavy Support
Dreadnought - 2 x twin-linked autocannons & psybolt ammo
Dreadnought - 2 x twin-linked autocannons & psybolt ammo
Tyranids "Hive Fleet Undercoat" - 1,500 points
HQ
Tyranid Prime - lash whip & bonesword
Elite
7 x Ymgarl Genestealers
2 x Hive Guard
2 x Venomthropes
Troops
Tervigon - adrenal glands, crushing claws & catalyst
Tervigon - adrenal glands, crushing claws & catalyst
10 x Termagants
10 x Termagants
10 x Genestealers
Heavy Support
Trygon - adrenal glands
Carnifex - 2 x twin-linked devourers
Game: Capture and Control + Pitched Battle
Deployment
Dave won the roll off and went first placing his objective top right corner in a ruin. I placed mine centre near my board edge so his Ymgarls and outflanking Genestealers cannot get it or appear in the thick of things. Dave deploys a Tervigon and a unit of Termagants near his objective hiding behind the ruin, everything else deploys in the centre using terrain mostly for cover.
I deployed my horde of Rhinos in a line between two terrain pieces along the board edge, one terrain piece held my objective. I had two Rhinos in front and the two Dreadnoughts as well.
* Tactical Notes
Right Dave has deployed 12" away from his table edge so I'm kept my forces back to avoid assault, I'll try and put as many wounds on him as possible before he reaches assault though my shooting of psycannons will be down as I'll have to move the tanks a little bit in case the Genestealers come in and I don't want them auto hitting.
Plan is to tackle everything in my face and then move out to the Tyranid objective. I'll go for the Tervigon to stop giving out feel no pain and free troops plus when this dies it will kill some Tyranids. Hive Guard are next, Tyranids cannot assault me if I'm in tanks and then the Trygon as it can move quickly and bust tanks open. I'll deal with the Genestealers when they arrive.
Turn 1
Dave moves his horde forward using terrain to get cover and keeping his Venomthropes close to the big bugs and behind some Termagants for cover saves. Tervigon on the objective spawns some Termagants, only a few and burns out. He casts feel no pain on the Hive Guard and on another unit, I think the Tervigon on the objective.
Shooting Hive Guard blast a Rhino but hardly hit and then fail to do any damage. I think that's about it.
In my turn I shuffle the Rhinos about but nothing major and shift the Dreadnoughts around so the Rhinos can move about more freely.
Shooting autocannons instant death the Venomthropes, both are toasted. Tervigon gets blasted by autocannons and psycannons knocking two wounds off it. Due to range I have to split fire putting two wounds on the Trygon and two wounds on the Fex-Star. I get some pot shots on the Hive Guard, they take a wound but it is saved thanks to feel no pain.
* Tactical Notes
A good first turn seeing the Venomthropes I.D, at least monstrous creatures won't be getting cover save so I'm glad I nailed them first and put them out of existance with psybolt autocannons. I wish I could have focused fired more on the Tervigon instead of dishing out wounds on other monstrous creatures, if those wounds would have been put on the Tervigon it would have been dead which would have been nice.
Next turn I suspect the Trygon will be in assault so when it comes in I'll have to bail a few squads out and unleash everything on it I can. I'll still focus on the Tervigon and Hive Guard to stop Dave ripping open my tanks and stop spawning troops.
Turn 2
Dave calls for reserves but nothing comes in, he then moves forward spawning more Termagants, feel no pain is cast on the Tervigon itself while the Hive Guard get feel no pain again. Trygon zooms forward ready to assault.
Shooting Hive Guard don't do nothing again, Carnifex does better scoring crew shaken on a Rhino. Trygon runs towards Rhino holding the Strike Squad and Inquisitor.
In assault Trygon explodes the Rhino, Grey Knights are all ok.
In my turn I move the Inquisitors squad through terrain ready to blast and assault the Trygon, it can eat force weapons

. I bail out a squad of Purifiers for support while Rhinos shuffle about to stop getting auto hit as one Dreadnought moves into terrain onto my objective. I try fortitude power on the shaken Rhino but it fails the psychic test, luckily wasn't a double 6
Shooting I unleash a torrent of fire power at the Trygon, it takes some punishment but two rending psycannon shots finish it off. I fire at the incoming Fex-Star and put another wound on the Carnifex and one on the Prime too, in fact I think the Fex takes two wounds. I manage to also put another wound on the Tervigon thanks to feel no pain and put a single wound on the Hive Guard, damn feel no pain!
* Tactical Notes
Ok I've taken out that Trygon and got two squads exposed to assault, luckily the Purifiers are in terrain and Tyranids don't have frags...
Next turn I'll put pressure on the Tervigon and hopefully finish it off and deal with the Fex-Star as it's on my doorstep now. I'll have to tackle the Hive Guard next turn or only if I have enough guns. Fingers crossed those Genestealers don't come in yet either..
Turn 3
Dave calls for reserves and only the Ymgarls arrive put they pop up on my objective, they move through cover ready to get into combat. Rest of the Tyranid horde moves forward with the Tervigon spawning more Termagants but it burns itself out. Feel no pain is put on the Tervigon and Hive Guard again.
Shooting Carnifex fires at a Rhino and scores crew stunned. Hive Guard just pitter patter a Rhino and do nothing, again. Termagants fire into the Purifiers killing one while another squad fires into the Inquisitors unit putting a wound on the Inquisitor.
In assault Ymgarls multi assault the Dreadnought, a Rhino and Inquisitors squad making the Rhino go boom but nothing really happens thanks to the Genestealers +1 toughness and power armour saves, though the Genestealers kill two Grey Knights with rending wounds - combat remains on. Termagants charge the Purifiers, only one Purifier left who remains in combat. Fex-Star charges the shaken Rhino and wrecks it, squad is forced to emergency disembark as I cannot get them all around the exits :( .
In my turn I bail out the other Purifier Squad which moves towards terrain to move into combat with the Genestealers as the Strike Squad out the exploded Rhino moves through terrain to backup the solo Purifier. Remaining Rhinos shuffle about ready to unleash a torrent of storm bolter and psycannon fire, another Strike Squad bails out the Rhino using the Rhinos to shield them from assaults and fire power from incoming Termagant horde.
Shooting I blast the Fex-Star with pretty much everything and wipe out the unit. That's all from me on that one.
I move the Purifiers into combat who cast cleansing flame killing four Ymgarls before the fight even starts, they then kill another one with halberds, the Genestealers fight back ripping the Inquisitor to pieces with rending claws and killing a Grey Knight from the squad they was already engaged with but ultimately force weapons pave there way of destruction - Purifiers consolidate stopping in terrain as the two remaining Grey Knights move onto my objective to claim it. Squad which moved from the wrecked Rhino charges the Termagants bashing the single Purifier, both squads try psychic powers but shadow in the warp is strong thanks to the Tervigon. Termagants take a beating but remain in combat.
* Tactical Notes
After Daves assault phase I was getting worried as he had tied up my Dreadnought in assault along with a squad plus his Fex-Star was on my doorstep which had just smashed a Rhino to pieces and the squad out that tank sitting 2" away from them ready to be eaten! Luckily I turned things around with the Purifiers adding to the fight and dealing massive damage thanks to cleansing flame, the Fex-Star also went down to mass fire power which took some doing but I did it, though storm bolters aren't exactly scary
My plan is to blast the Tervigon to stop shadow in the warp and finish off Termagants for me, I'll go for the Hive Guard and move up Rhinos towards Daves objective.
Turn 4
Termagant horde moves down the board to get more into assault with the Tervigon trailing behind. The last Genestealer unit also arrives from reserve outflanking on my right hand side, luckily nothing is there for them to threaten - yet.
Shooting Hive Guard explode a Rhino, finally they do something! To make up from earlier two Grey Knights are killed in the blast, Termagants follow up the volley leaving two standing who fail morale and run for the hills. Purifiers get shot by Termagants but all are safe. Unit which emergency bailed out the Rhino get shot by Termagants but all are safe.
Assault, Termagants charge the Purifiers, they go last as the Purifiers are in terrain and they all die thanks to no retreat saves. Termagants against the single Purifier and supporting Grey Knight squad get finished off while the Termagants which just charged the pinned squad do nothing but combat remains on. Two man squad gets assaulted by Termagants and are beaten leaving nothing to hold my objective.
In my turn I move the single Purifier to assault the Termagants while the full strength Purifier unit moves through terrain ready to shoot the Tervigon. Squad which just assisted the single Purifier in combat move and claim my objective while another squad bails out the Rhino and moves to shoot the Tervigon as the unit falling back regroups and stops in terrain.
Shooting I blast the Tervigon and rending psycannons bring it down, it deals death to Termagant units though both are still going. I blast the Genestealers killing two of them.
In assault solo Purifier charges and wipes out the Termagant unit. Strike Squad locked in combat with the other Termagants wipe them out.
* Tactical Notes
It's going well but looks like this game will be a draw. I have a few operational tanks but that won't get near Daves objective until turn 7, and that's if the game goes on that far. Daves only chances of getting my objective is with the Genestealers and Termagants and to be fair both units have a wall of Grey Knight shiny armour to go through.
My plan is to keep the squad and Dreadnought bunkered down on my objective and block off my objective with Purifiers. I'll blast the Termagants and assault them and fire the other Dreadnought and tanks into the Genestealers to finish them off.
Turn 5
Dave does synapse tests for the Hive Guard which pass so do the Termagants. He moves the Hive Guard back to avoid Grey Knight force weapon bum robbery and the Termagants move to shoot and assault them while Genestealers move out of terrain.
Shooting Hive Guard fire at something, might be Dreadnought though nothing happens. Termagants blast the Strike Squad which take 25% morale and fall back which means they cannot be assaulted now

.
In assault Genestealers charge the Dreadnought, a Rhino and the two man squad in terrain. Two Genestealers die thanks to the Dreadnought kicking his feet and a Justicars force weapon, though Dreadnought is immobilised and crew shaken and the psycannon armed Grey Knight dies - combat remains.
In my turn I regroup the squad falling back and they move to shoot and assault the Termagants along with the super solo Purifier. Strike moves from the near the table edge to blast and assault the Termagants.
Shooting Hive Guard eat psycannons and die wiping the squad out. Termagants wat storm bolters but hang on in there as I didn't do a lot of damage.
In assault Termagants die, Justicar dies, Dreadnought hangs on.
At this point we call it a day as if the game goes on anymore it will be a draw. We roll for it to be sure and game ends.
Summary
Interesting battle against a horde army. Staying back worked well letting Dave come to me and I could gun him down, shame the psycannons range is short and I couldn't put all my shots onto a single target. Though staying back ultimately stopped me from getting near Daves objective as the one tank I was going to use Dave wisely blown up.
Grey Knights performed well and I like the mix of combat and shooting but boy do I miss feel no pain from Blood Angels! Having small squads is good for saturation but problem is they don't last long or when they take a beating there numbers drop quickly. So I think I will try full squads of Grey Knights and see how that works and then at least if they are popped out the tank then they have numbers to take a hit. I liked the Rhinos better, I'll be keeping them. Inquisitor is ok for cheap
HQ I forgot about rad grenades, doh, could have been a slightly different result in combat against the +1 toughness Ymgarls. Inquisitor is too weak with power weapon and hammerhand didn't happen so I'm going to take a scythian venom blade which wounds on a 2+.
I think I'm getting sorted which direction I want to go with Grey Knights now, it's just down to a case of getting it finely tuned. I'm thinking if I take full squads I'll have about 70 points left which is enough to put hunter killers on all Rhinos. I know one shot, but adds anti tank/monstrous creature and are unlimited range too.