Fun game when it works; shitty networking code sees to it that it frequently doesn't. I probably need to play more of these things but, otherwise, this is the worst networking and matchmaking system I've had to deal with in terms of lost connections and lag. When you can't even stay connected, let alone connect, to the matchmaking "Lounge" consistently something's seriously fucked.
From what I can tell the problem is that there's not so much dedicated servers as a system of players individually acting as hosts once the matchmaker declares them as such. This means your ability to stay connected to the game often relies on the bandwidth available to someone else's PS3 or, if you're really lucky, being declared the "Host"; in which case you'll likely be able to play to your hearts content while others get the joy of being kicked from your piddly ass connection throughout the match or crawl along as Laggzilla. Oh, and when your Host rage quits after getting spanked for the 10th consecutive time? Out to the lounge ye all go...
Yeah, that's there's the height of graceful failure code design.
Otherwise, you get kicked a lot and it won't really matter if you DMZ, Port Forward, or just slap your PS3 at the business end of your modem and pray because the game simply can't handle 10 players for significant stretches of time unless you luck into someone with a T1 into their house. You are gonna spend a shit ton of time trying to connect to a match, and even more being kicked out to try and get back in again.
Which is really unfortunate because the multiplayer is solid otherwise.