I totally sympathize.
I have gotten so used to banging <cmd><space> to switch apps as a sort of punctuation to my work flow that my keyboard has started to show signs of wear specific to <cmd><space>. Specifically, part of the cmd squiggly is gone.
Back when I was using LaunchBar on cheap PCs running OpenStep (good OS makes bad hardware passable), I hit <cmd><space> hard enough that the space bar on the cheap PC keyboard went flipping across the room. That was fun.