Never had a LP, but had same pups in my PRS.
Rebel Yell has less output, more highs and high-mids, bright and crunchy pickup, tighter than HD, more thin sounding.
HD is fatter, but not that crunchy, more polite (but still have some cut), has more center-mids.
Depends on what gain levels you need... for progressive-rock/metal I would definitely take HD, but for hard-rock/hair metal I prefer RY.
Although, among "mid-pushed" BKP pickups I dig Crawler a lot more, than HD and RY both. Crawler is less modern than HD, but has almost same output, thicker sound, and it roars! And very good smooth\thick lead sound, extra weight on notes, played higher than 12th fret. It's my favorite BKP until now, and I've tried Nailbomb, Cold Sweat, HD, RY and Emerald (also great PU, less output that Crawler, brighter, but have awesome articulation and mid-push).
Emerald neck/Crawler bridge would stay in my Suhr forever, although Crawler might be a little too dark in LP.