Liko's post above is a good one. Definitely take that into account if you're worried about cleaning them up. Honestly your amp probably matters a lot more than the pickups.
I currently have them both. I would say "nice tight low end and lots of clarity" more accurately describes the Nazgul. The Pegasus is a warmer pickup in comparison, a bit more robust on the bottom end. In direct comparison, I would say that due to the Pegasus being a bit bassier, it's actually a little less clear due to the bass strings sort of overtaking some of the higher notes on big chords. (Again, that's in direct comparison, it's not something you'll really notice on its own.) I'm not saying that as a negative either, it's just a different tone, sort of like comparing different colors, neither is better, just different. Just depends on the person, since it's all subjective anyway.