I switched to console because maintaining a gaming PC is too expensive and consoles get a lot of exclusives that either dont make it to PC or take awhile to get there.
I personally think XIMs are too expensive. 5 to 6 hours a week is actually not bad, its probably more than I get to play. So maybe it would be better to ease into it. Try a third person shooter instead of a first person one. 3rd person shooters arent as big a jump when you go from M+K to a controller. Perhaps give Uncharted or Dead Space a try. Once you get comfortable with that it should make the jump into 1st person shooters easier. Once you get into FPS, maybe stay away from the faster shooters. I personally thought Killzone 2 had a great feel with the controller and its a bit slower than say the MW series, but perhaps others can make some suggestions.
I see where you are coming from with your analogy, but once you learn to ride a unicycle, its a lot like riding a bicycle in that you never really forget. If you learn now, you wont have to buy another XIM when the next gen of systems rolls around. In a sense you may just be delaying the inevitable and spending a lot of money doing it.