I'd like to see a new filter added for the servers (at least for COOP, but both would be better) where you can select what side you want to play as.
For example I never want to be on Team Haji, so a pretty good amount of my time is wasted by joinging an insurgent coop, then leaving, joining it again and leaving again.

I can understand that for PvP this might be a bad idea (although the filter can always return with no servers found for your specifications), but for COOP this is a must.