When the most intense part of F3AR is the MP it probably means the SP campaign may not be as intense as say the original which is sad.
I'm guessing from the look of it, that the campaign is not only designed for, but recommended to be played in Co-op. This is great if the levels aren't designed to be won by objectives that rely solely on teamwork alone. Kinda like Army of Two or to a lesser extent Cain and Lynch.
So far I'm not to impressed with it the game play is more like Call of Duty. It's been straight battle but at least they took it out of the hallways. I've only been playing it for a few hours and so far I've been in a prison a sewer and now I'm in a village.I'll see how it goes.