Marvin, I have the 9000FII, and I like it ok. When I bought it, I had no plans or expectations of every going to 4x5, or anything larger then 120. About 5 months after getting it, I got a 4x5 Calumet....
I've found it to be difficult to stitch the 4x5. It's not the stitching part, but it's the exposure part of the two sides of the negative. Using the Canon software, it seems even with no adjustments set, it still applies some adjustments that I can't seem to avoid. The result in my experiences, has been a slight difference between the two sides in the exposure, and is noticeable and almost impossible to fix when stitched.
One thing I'm looking into is getting the BetterScanning film holders. The supplied holders suck for 120, especially if is there is any curve in the film width-wise.
480sparky, can you post a pic of the cut-down MF carrier?