I have been playing Battlefield 3 for XBOX 360 with the XIM Edge. Before playing I was at a .79 K/D and falling fast. Now that I have been using the XIM I have ranked up from a level 3 to a level 37 in about two weeks and my K/D is a 2.02 and rising fast. Typically I go about 50-5 in a game.
My settings are a little different then what I have seen people use though. I wanted it to feel like plaing PC so if I move the mouse about half an inch the character will turn 180 degrees.
I never move the mouse more than 1 inch from the center of the mouse pad. I dont like the idea of having to slide the mouse all the way across the pad to turn around.
With in game sensitivity turned to max I also raised my HIP to 90.0 and ADS to 80.0. To me with these settings it feels just as if I am playing on a PC.
I know these settings seem high, but try it, they work great.
I do get red flashed from the XIM when I move to fast, but I never feel it in game.
So, for anyone playing Battlefield 3 on XBOX that thinks using the mouse is a little sluggish, try those settings. You wont be dissapointed.