It has its' qualities to make it such a playable, fun co-op game but my goodness... Not sure if anyone else is suffering with the same sort of issues but I ran into high ping which made things unplayable for the first 15-20 minutes until it stabilized, then sudden game crashes, and lastly fps drops.
I try to like the game, I actually kind of prefer it over Left 4 Dead 2, but the performance instability is what discourages me from recommending it to others and just having a general good time when it's opened. Sucks the developers have moved on so soon...

Boring 4 Playing

Left 4 Dead 2 better