An 80mm f1.9 D or better yet LS with say 1/800 flash sync would really be something, I agree. Rollei did the right thing I think with slower leaf shutters for fast lenses.
Medium format in general seems to be stuck with rather conservative aperture offerings and even those few that exist are old, manual focus and tricky to use on high res digital.
And whats with Phase leaf shutter lenses having five aperture blades? I mean seriously they could do better than that.
RZ lenses are dope indeed, though the 645 LS lenses are extremely good too. I find the 80LS and 110LS (and 55LS from the samples I've seen) render very similarly to the RZ 110mm, while the 65mm L-A and 210mm APO render differently. I would describe the RZ lenses as more "cinematic" while the LS more "modern". The differences are subtle but they're there. Its all good glass.