First off I think you misunderstood us. When we said this list is nothing new, recycled, etc we're not saying that as a necessarily BAD thing. It's just a very common list and a lot of competitive veteran players have seen it and know how to deal with
IG's AV12 spam in general. I think the changes to your list have made it more individual, but worse.
Harker is great for getting those rear armor shots or delaying enemy troops. Infiltrate him on an enemy's flank and the enemy either has to deal with him or has to suffer many turns of side/rear armor shots, thus Plasma's range mixed with an
AC make him pretty great. Sit still in cover and you get that 24" range mixed with Stealth
USR.... mmmm. If you face an army that goes full reserve he's still alright to put him midfield but not as great.
Plasma spam on vets makes them kill themselves too often and 15 points on a gun is pretty tough for a guardsmen. Unless you have a specific role for them (Like with Harker or in an outflanking Valkyrie) it's just not worth the points. I think Melta is better. +1 S, +1 on damage table, plus the melta rule (duh) is pretty good. I originally loved the idea of plasma over melta, but after putting into practice it isn't as good on paper as it is in practice. Plus melta
IDs Nobs and Paladins, which in my metagame is VERY important

(I can't wait to play the tyranid player who brings lots of Tyranid Warriors. It'll be glorious)
I agree that the lonely Manticore is gonna get nuked and that
HF's on the Chimeras are probably still a better bet. It would be sensible to give it camo netting, though I'll rarely say that.