Well it's gone back and proved to be an interesting device to use.
The focal length of the 28+HTS is somewhat longer than I'd normally choose, but I was pleased with the results
If anyone's curious I've written up some notes at
http://www.northlight-images.co.uk/hasselblad-h6d-50c-and-hts-adapter/ I wouldn't claim to do a detailed review of unfamiliar kit in a week, so it's a fairly broad overview.
What I liked (compared to the various TS-E lenses I regularly use) was the precision in setting, and particularly having the rotation with 15 degree stops rather than the 30 degree steps of the TS-E (which makes setting to 45 degrees imprecise). Locking tilt at zero took a bit more effort than I thought it should, but my only real complaint (and not a huge one) is that the tilt and shift axes are fixed with respect to each other.
Oh, and I could do without that 1.5x focal multiplier - I use shift mostly for architectural work, so wide often helps.