Like absolute, drop-dead feminine beauty in a spouse, many things about lens performance are hugely overrated. Yes, WA lenses on Tech Cams outperform WA lenses on Medium Format DSLR's, but by how freakin' much? At the end of the day, it's about the pictures, not whether the images please pixel-peepers.
I own a 35mm Mamiya lens for my Phase One with a P65 back. Nearly all of its shortcomings can be repaired adequately enough in Camera Raw and other software is available. The images I've made with it are often, often, the ones that get the highest kudos when exhibited. Much of that is due to the fact that almost all photographers take better pictures with an SLR than with a view/tech camera, especially when light is on the move or other challenges present themselves, like cramped POV, low camera angle etc.
I was stunned when I looked at the 32mmHR vs. 28mm Schneider leaf comparison. The 28-leaf is a lens I could not only live with but happily use. Yes, 6 grand, yes, you must have a DF body, so for 10-12 grand, (price the Arca RM3di with a 32mmHR with viewfinder, focus-unit et al) and it emerges as a bargain, esp. since you see an image, right-side-up, not reversed, choice of AF or manual focus--quickly, what you see is what you get, push the release.
I've never spent time with the Arca/32HR setup, but I have used a 4x5 with the 72XL and I can say without reservation, the camera limits the photographer and makes for fewer dynamic images.
Bill O'Connor