I'll just add to this that my friend Bill Atkinson, one of the most respected people in the industry when it comes to both technology as well as photographic credentials, has switched from a Hasselblad H system and lenses to Phase One. So has Mark Dubovoy, a widely exhibited fine art photographer and teacher. And if you've noticed, I have some small interest in ultimate image quality and I now shoot with Phase cameras, lenses and backs.
Oh yes, so does Jeff Schewe, Charles Cramer and Tim Wolcott, all of whom are widely respected both for their photography as well as their technical acumen. Give me a few minutes and I'll think of a few more. So, taking the position that there is something about Hasselblad H lenses that puts them on a different plane than Mamiya / Phase lenses is simply unsubstantiated posturing.
Now if you want to talk about great lenses, have a look at the Schneider Digitars or Rodenstock digital lenses for technical cameras. But, that's another story.
Michael