I've noticed that Gamestop has the PC version on sale for $30 so I've been comtemplating picking it up.

I've already rented it on the PS3 so I'm already aware the the single player campaign is boring and forgetable. This is mainly a quality check on the multiplayer. Is the multiplayer still holding up? Are there lots of players and everything? Are there a lot of bugs, exploits and such present?

I played it on PC, but only single player. No bugs found as far as I remember, GPU heavy on higher settings (almost as much as Crysis or Stalker). Can't really comment on mods and such, since I've already stopped playing it.

They recently released a patch that was months overdue, but the game is far more than playable. I have put 5 1/2 days into it and have enjoyed just about all of it. Just make sure you have a computer that can run it properly.