OK, so I've had my U from Hell for a while now, and was digging the DS7 to start of with, but, have the following issues with the sound of it in the guitar:
1) The guitar has a LOT of low end resonance, and I mean a LOT, that overpowers the top end, and the DS7 just doesn't give the top end the help it needs to sparkle through
2) Too tight, really does feel a bit stiff in overall feel, however, weirdly, it's only for soloing that it's too stiff, as the low end of the guitar (the resonance) really compensates for the stiffness.
So, what do I want? A more rocky pickup, that'll tame the low end of the guitar a bit, and get the top end more present, and not be as stiff in overall feel.
Also, I want a passive pickup, and preferably one I have a chance to get in trade for a pickup I have now (which kind of fules out BKP's unfortunately), so basically a Seymour Duncan, or a Dimarzio or the like!
Crunch Lab, maybe? From what I've heard, it seems to basically be a D-Sonic that had these issues worked out of it. I think the top end is also taken down a bit, though, so that part may be a bit counterproductive to you.