Been playing this a bit on PC on high settings. Quite enjoying it. I didn't get too far on the 360 version TBH so still going over old ground at the moment and for £2.50 or so in the Steam sale I couldn't let it slip.
Using K&M which is a little odd coming from a controller but I have a Razer Deathadder mouse with two customisable buttons on the side which I've mapped for E and R (open and reload respectively). Still, getting used to it, but I'm struggling a little in gun fights switching between forward and backward so I end up usually going all gungho or just running forwards and using the mouse for direction.
All good though, just takes time I guess.