I have always wanted to try using a PC9 or similar with a red-dot scope and some decent 20 round mags for defensive work. I imagine the PC9 and PC40, being very rugged by design, would lend themselves very well to such an endeavour.
I still may try to do this sort of setup on my Camp Carbine in 9mm, even though it is not quite as rugged as its Ruger counterpart. Then again, there are few guns which are more rugged than Rugers!