It's flawed, stupid fun. They did patch the game post-release to fix some of the issues, but there are still problems with the game. You should be able to still find games to play in campaign, but it can be slow at times.
I assume you are talking about the 360 version, but don't buy the PS3 version, not even for $10. It's shit compared to the 360 version...slowdown all over the place and laggy online does not make for a fun game.
I'd pick it up if you're interested in the online multiplayer (deathmatch); don't buy it for the campaign mode. That's not the focus of LP2.