To be honest I just got it for the GSL, but I'm actually really enjoying it, it kind of reminds me a little of Bioshock. The graphics are pretty good, especially on some of the characters and the weapons are awesome as well, plus its kinda scary.
Hope that helps with, erm, whatever

If you can pick it up cheap from anywhere (I'd say $10 or under) then buy it, otherwise I'd say rent it, as all the achievements can be gotten in one playthrough, which takes around 5-10 hours.
