I use GHS Pressurewounds, the 'ML7200' set (.044-.102), on my Ernie Ball Music Man Sterling HS and my '88 Japanese Fender Jazz Bass Special (P body, J neck, P/J pickups, TBX tone control) fretless. Historically I've always used Warwick EMP (coated stainless roundwounds), and have always been happy with them. When I got my Sterling, however, I realized I kinda needed something to tame the high-end zing a bit. I despise the feel and, to a lesser extent, sound of flats, and a great deal of research led me to try these things out.
Man, am I glad I did! For my gear and style, there's no way there's a better string out there. They're deep as the ocean without being muddy, the tension is delicious, there's plenty of brightness there if I want it, amazingly responsive, ultra-punchy in the midrange, super well-balanced, just the right amount of finger noise, last forever... On and on. They're hex-core and the compressed wrap wire is what they call 'Alloy 52', which seems to me to be stainless for all intents and purposes.
If anyone thinks there's any chance that these babies might be what they're looking for, try a set as soon as humanly possible. For me, they're the end-all, be-all. I'm really bummed out that it took me 15 years of playing to learn about them.