I have no clue when the Demon became a "fan-favorite," I thought everyone hated it.
I love it though; I don't think it's too bright, but I'm a person accustomed to 1 meg pots and single coils. If you are mostly a single coil user, I think the Demon gives you everything you "want" in a humbucker (more output, more bass, somewhat more compression and mids,) while retaining familiar aspects such as clarity, dynamics, and attack. The 59 to me is a much "rounder" sounding pickup, the Demon more "solid" and less forgiving. It avoids honkiness and looseness vs. a lot of PAF-level pickups.
59n, Jazzn would probably work with it, but I like a single coil neck position with mine. I do want to double-Demon a guitar at some point, and reverse the coil screws on the neck position for a clean look.