I just built my first MAME cabinet and when I found out I could use the lightguns to play shooting games, I GOT REALLY EXCITED, until I saw it was $200 + shipping for the ACT-LABS guns.
I've got a WII and 2 wiimotes w/wireless sensor bar, so if I can make those work with my cabinet/games, then I will.
Since I already have the wii controllers I would rather go that route if all I have to buy is a bluetooth adapter, but how good is it?