I'm 100% preloaded since Friday/Sat here. I got a killer deal of 25 dollars for Bioshock: Inf, Xcom: EU (Which I sold to a friend for 8 dollars) Mafia 2(Only game I didn't Have on the list), and Bioshock 1 (Which I gave to Turin), and the game is looking to be awesome. Im stoked.
As for Pad Vs Keyboard, different strokes for different folks. I havent played many console games until recently and Im having the opposite effect, especially with precision games like Trials Evolution Gold for PC, after a few hours of playing my hands ache like nothing else, since I'm not used to using a gamepad. But in the sense of this being a mainly SP experience I don't think anyone can fault you, if the options there.
Myself, I will be using KB/Mouse since I fail hardcore at console FPS and I'm better with K/M setup.