I own a B22 and a D5. In fact, I also have a Chromega B, which is the color head version of the B22.
The only reason I bought the D5 last year was because it was available for $100, and I thought that I might one day move up in format. I presently have 35mm, 645, and 6x6. Still using the same lenses, so the prints look the same.
Keep the B22! (even if you move up some day )