a) You notice the lag, much moreso that a PC game.
b) There are still someplaying GTA IV, I'd bet RDR has more. I haven't played LBP in ages, no idea, it was terri-laggy.
c) There is Home, I haven't used it since it came out mind you. You can get demos, chat, DLC stuff, same as xbox pretty much.
The multiplayer really depends on the game, some have great online (MGS4.. well in terms of lag anyways, shooting + console = herp a derp), while others are almost unplayable (LBP), others you can enjoy, but don't expect it to be top notch (running people over in cars in GTA IV online is almost impossible since they aren't where you see them). Voice is all about whatever bluetooth you buy as well, I haven't found many people with quality ones.
