As a user of both a D2x and a Mamiya ZD, I am not sure to understand what is so different between these 2 in terms of product.
Now I understand that MF buyers might have different expectations in terms of support (uptime requirements,...), but I don't see why
It very much depends on what your shooting. If you just shooting to cards and downloading to folders and processing a few files, then yes the workflow for the d2x and a medium format back are quite similiar.
But if you are working in a room with 11 clients two monitors, tethered, batch processing in the background, changing color, setting input, output values, naming files, sorting files, etc. etc., then someobdy has to be very good at the computer and the workflow and must know it front and back.
V-8, lc10, C-1, flexcolor take a while to learn and all have some hidden, esoteric settings that you must be dead on right, or you will open yourself up to a world of hurt.
that's why so many photographers hire techs, or either learn it themselves or both.
I recommend both and a good dealer or tech service company can walk you through many of the issues.
Remember, medium format backs do not produce that good of an in camera preview and just to get to the first web gallery requires some form of batch processing.
I can give you 12 different sceanrios that can throw even the best workflow out the window.
The tethering shuts down and you must shoot one session to cards, or the client wants to edit on the fly, or the naming was wrong and must be changed after shooting or all of the above.
A good dealer like Steve Hendrix and Dave Gallagher can be a lifesaver and not rip you off in the process.
I am sure there are other good dealers but those two I know personally and those two will be there to help or find the person that knows the answers.
These aren't just cameras, these are cameras with drum scanners attached to them.