Taken from the blog > http://imperiusdominatus.blogspot.com/2009/10/ork-deffkopter-tactica.html
The previous nasty metal Deffkoptas were over-priced and fell apart, but now the ork deffkopter comes in a new plastic form which has been circulating for over a year. Now that these deffkopters are everywhere, like the other pieces of the AOBR box set, how do they fare in game.
The deffkopter is 35 points and for that you get the average ork profile but with the added bonus of 2 wounds and a 4+ armour save. Wargear includes a twin-linked shoota. They move as jetbikes so if they turbo boost (up to 24") they get a 3+ cover save. As jetbikes, they also ignore difficult terrain tests, unless they start or finish in difficult terrain, which then actually counts as dangerous terrain. For 35 points that's a good deal. Oh, and they get scout and hit and run rule too.
You can upgrade their gun to a twin-linked rokkit launcha or a kustom mega blaster for a few points. The mega blaster might be cheap but it's not twin-linked so forget about it. The rokkit launcha is the way to go. You can also get a buzzsaw, which is basically a power fist, and a big bomm, which is a large blast using S4 AP5 profile. The bomm you can use after turbo boosting, but only over a target you have flown over, and you can only use it once. It only scatters D6", but if you miss that's points wasted and for basically a bolter template it's not worth it.
I arm my deffkopters with rokkits and one buzzsaw in the unit, this way they can go tank hunting. With each kopter having twin-linked rokkits they become a dangerous unit. What's the point in having big shootas and moving that much and having scout? Just use them for tank hunting, popping tanks rear and side armour and be done with it. The buzzsaw comes in handy for assaulting vehicles.
What you can do is use your scout move, which can be up to 24". Then when it's your turn you can move 24" too. If you get the first turn your deffkopters can move 48" before your opponent even moves! Personally I'd turbo boost forward, but after that I'd get the anti tank shots in. So in addition to a 24" turbo-boost scout move, you can move 12" and have 24" range rokkits which gives a impressive range of 60" all together if you go first. Additionally, if you go first you will have a 42" assault range with a S7 buzzsaw. And remember, if it is the top of turn 1 you will be automatically hitting rear armor.
With scouts you can also outflank. This can come in useful for taking out vehicles on the table edge, but you've got to hope you come in on the right table edge. Is your opponent going to leave vehicles around the edge ready for you to move on and blow up? I don't think so. Outflanking isn't a reliable tactic for deffkopters, in fact it isn't a reliable tactic all together I don't think.
Deffkopters come in an interesting unit size, 1-5. If you take a unit of 5 it's costing 175 points before upgrades. Throw on some rokkits and your anti-tank unit is costing more than the tank itself, so it's not really making its points back. If you use all rokkits, few tanks are going to survive five S8 twin-linked shots. What about a smaller unit size, say 3? Morale becomes a problem now. Kill one and you've lost 33% of your unit, and if you lose 25% you face a morale test. They have a leadership of 7 which is an average roll, but they fall back 3D6 inches. This can be risky and if they leave the table, you've lost your anti-tank unit.
Here's a remedy. Take them in singles if you have the fast attack slots free. Give one a buzzsaw and hide it behind the others to get a cover save. This why when they are shot at only one unit can shoot at one at a time, so if your deffkopter takes 4 un-saved wounds, you only lose one If you had them in a unit you'd lose two. So taking them in singles but keeping them together works well for targetting and morale purposes.
Deffkopters are a simple impressive unit. Give them rokkits and one buzzsaw, keep them in single units to keep the wounds down. They kill tanks and do it well, that's all. Don't expect them to do a lot, but they can be really annoying. Give them some thought.