The only major complaint I have with the game in its current incarnation is the lack of ability responsiveness, as highlighted in this thread:
http://www.swtor.com/community/showthread.php?t=95738
I'm not positive if everyone's encountering this animation lag (I should think so), but it's making my PvP as an IA quite frustrating. It's as if I have 200+ ms when using my vibroblade abilities, when I have less than 50. Note the description in this youtube video:
http://www.youtube.com/watch?v=R1T0OisXdew
That's exactly what happens with me, as well. Anyone else having this issue?