I don't talk about them much here but when I see you guys talking about clarity and definition, I have to suggest Bartolinis. They are the only pickups that I know of that can actually add clarity and definition to a muddy instrument. I'm not calling the UV muddy, but that's your experience right now. It could be the amp, processors, or anything in the mix, including the guitar. (And I never liked my Blaze when I had it either) But I'm telling you how to fix it at the guitar. And it's not an EQ curve issue.
Bartolinis are in a different league when it comes to string-to-string separation and individual note clarity, and it's the way they're made. This is bad if you are trying to do Zeppelin or something where the mushiness is part of the overall vibe you're going for. But I see them as a must have for 7-stringers who are in that constant love-hate relationship with their B string. (or whatever else its drop tuned to) They especially improve note-to-note separation and clarity in those bottom three strings, where it's crucial. There's enough 7's to choose from that you'll get your sound. If you want a tutorial, like "I like the TZ, or Fred etc. so which model should I get?" I can probably tell you.