Not sure how the PSN community is, bt the Xbox side really only gets any play on Survivors (the worst mode in the game). The others are more or less dead. You can find maybe on or two games hosted at peak hours. I can't imagine PSN being much different.
They really aren't worth the time honestly. Onslaught and Siege can be fun, but the lack of people really hurt it. --- "No man should fight any war but his own."
I think Survivors, Campaign, and Mercenaries are the only active modes atm. I haven't played RE 6 in a while but the other modes weren't active at that time. --- Waiting for Castlevania: Lords of Shadow 2 and Watch Dogs. http://psntl.com/user/view/gmoshier