@Pascal: I agree with you regarding the HY6 - the new back adapts to more or less every system from history too now, only except Rollei 6008 and HY6. I don't understand this too. OK, developing an AFI-version parallel might be too expensive given the small number of cameras around, I agree - but (in case the firmware of HY6 doesn't lock out other back than AFI and Sinar, and even this shouldn't be a problem for LEAF, as they own the specs of HY6, so far I know) it should be quite easy to produce a back that just fits to HY6. Not as much integrated as it was with the AFI (need for 2 batteries in example), but it could work. Make the back rotating (might be easier than the rotating sensor, though this of course is the more elegant solution), and all AFI-users would be able to upgrade/replace, if needed.
I also would like to see Phase-Backs as an option - but this of course is not up to LEAF...
Andreas - had a Sinar HY6 rented for a weekend and, well, I love it