The killstreak hack with support on assault killstreaks are patched, but ive played a game this morning with russians in the enemy team and they seem to get it work... one guy had pred , reaper and pavelow, and he died more then he made kills, no care packages heard..
Then what's the point of using the trainer to do your classes?
Well, I personally use it when I've made all weapons level 31 and I can't choose the attachments I want, because it only updates after you shoot someone in-game. This way I can choose the attachments beforehand and have them all by the second round. I'm not really aware of whether or not the trainer has ever been able to force attachments on, but I think it has and was patched. Now it's just a good way of editing your custom classes for weapons you haven't played with yet.