You can. I have one plugged in and move the analog and my guy started running. I can't bring myself to use a controller for anything but difficult helicopters (gta) or platforming games but it does work.
As far as I can tell this game is running amazingly smooth with everything turned up and 4x msaa, can do 8 but I notice a litter stutter driving around at high speeds. The game world looks to be the size of GTA IV but run so much better (though it doesn't look as real). As for gameplay this thing is so over the top that I'm in love with it. I've spent two hours just messing around and I'm so glad I preordered it.