I have a SUB and a Sterling Ray 34 and have swapped out the pickups on both. The SUB just sounded muddy and the Ray 34 a bit too shrill. Managed to get a Delano for the SUB and it sounds brilliant. Versatile and no distortion at all. Put a Nordstrand in the Ray 34 at that sounds lovely too. I now have two great sounding and playing basses for less than the cost of a battered used Stingray. OK, the SUB finish is a bit basic, but it plays well.
The preamp in the SUB is very hot, but I think the issue is with the pickup rather than the preamp in both, based on personal experience.
Might try a different preamp in one of them to see if it makes a big difference, but generally happy now the pickups have been switched over.