If you have friends or people to play with, it can be lots of fun at times. Used copies usually go for $10 dollars now, so even if you end up hating it, it's not a big loss.
I got 1k score on it within the first 2 weeks on my own, without boosting, really. The gameplay can be a bit repetitive and there aren't too many maps to choose from, and that's really where the bad reviews came in (that and the fact that half of the people who purchased it at first were CoD players and suck at team oriented games). But if you have people to play with, and if you like team based shooters, then I'd say go for it.
Gaze across the vast star ocean and pray to me!