I play an AP PT and have to admit that I feel a bit OP at times but I wouldn't say I'm the most OP compared to an assassin who knows what they're doing. My burst is fantastic, but I don't feel like people have an issue shutting me down if they really want to.
I would say OP right now goes:
1) assassin
2) powertech/sorc (I dont see as many sorc played that well though, most seem sort of bad)
and on Juggs, I don't currently feel like they are OP. They are more on the balanced side of things right now.
I can't talk for other classes, but I feel the OP PT issues just come from the way shoulder cannon and some of the burst is set up right now. I don't feel that AP PT is nearly as fantastic in PVE.