I can't compare MP because BF3 is the only MP I played (first onen too).
but it really is a blast when you get a good team. I've had friend requests after a really good session with people who play it the right way. I'll get invites to join a game from various friends, and nearly every time it's awesome.
It can get frustrating with randoms; but it's like golf - you might hate your round, but then you get that 'one' shot from 160 out and about 3' from the hole....and that keeps you coming back. Once you experience a really good team and strategy, you'll love it.