Couple of issues:
-BF3's horrible team balancing issues haven't been fixed. Far too often matches are one-sided almost. My games last night:
Rush (attacking)- team can't destroy a single MCOM
Rush (defending, same map)- attackers win easily
Domination (300 tickets)- team loses by 200+
Domination (300 tickets)- team loses by 200+
Also, not sure if it's lag or poor animation, but I frequently get insta-killed, by all types of weapons. I'll empty half a clip into somebody from behind, only to die as soon as he turns around. Happens a lot.