Buy it for massive fun. It was just about the laggiest, though. I don't play online games on the PS3 aside from previously having played killzone 2, is this the quality across the board, or is it just because it's new and experiencing battlefield 1943 syndrome?
I did not encounter any serious lag in my two online sessions.
Sony really should have packed a headset in with all PS3's. I hate that I would have to drop $40-60 on a bluetooth headset just so I can communicate with teammates, an essential part of online gaming. I played a capture the princess game for ONE HOUR with neither side getting the upper hand because nobody was cooperating.
It's still really fun, though. Did you also find that the Warrior class gets worse after its upgrade? You lose the shield and that charge attack rarely ever hits. I guess with him, as with all classes, the trick is to know when to change weapons/spells on-the-fly.