Nostromo N52 FTW..How I do it. I set up a profile for a standard FPS game, and use it for all games that are similar, that way the learning curve for each games remapped K/B control key positions are the same. In the past I had problems with my left hand, wrist and forearm getting cramps, not with the N52. My N52 and mouse are located at a comfortable level, on one of those roll out, under counter trays. No mouse pad here with my MX 518. I use a piece of very light burlap cloth [ heh, not sure what it is really called, I picked it up in the crafts section of Walmart ] stretched and framed with thin strips of wood, then screwed to the roll out, under counter tray. Not too purty..but who cares..it works.
Some of my games are listed so you can get an idea of the type that I play.
HL2, COD 1 2 ect, R6 Vegas, Quake 4, Far Cry..on and on.
To be honest..any time you change your game control scheme..you will have a learning curve. Yours may be longer or shorter than mine. Mine was a few hours of playing. Just stick with it and the new controller will become second nature to you.
There you have it.