Yep exactly, the Stab seems to control the power-in, so the Fuzz Factory pretty much has a built-in variable power supply.
Our guitarist had Devi's Disaster Fuzz, and it was very cool; it is worth mentioning that he did in fact get a variable power supply for it because it wasn't doing exactly what he wanted. So there you go.
He recently dropped it from his board for a Dwarfcraft Great Destroyer though, I'm not sure why. Both sounded great though. It probably just didn't gel well with the new Awkward Bodies songs, not sure.
The guitarist in a different band I'm in has a cool boutique fuzz that sounds fantastic. I don't remember what it is though, I'll check it out tonight at practice.