I bought this for the PS3 today. Played until Chapter 4 with people watching. Great fun game. Completely immersive and at times spooky as well. Had me jump a few times.
As for impressions on the controller, I see no reason why this wouldn't translate over well to the mouse and keyboard. Personally I think the KB+M will be superior due to the combat being based on precision dismemberment.
As for buying it on consoles first, simply put, unless you're a complete nut for playing this on your PC alone, or go thorugh the hassle of hooking it up to a big screen via HDMI and the surround sound system (I can't, since my room with this PC is too far from the living room), the type of game - at least for me - is more geared towards consoles.
Having said that, I just might buy this on PC as well for the graphics, and what I assume, better controls.
It's a pretty good game.