Thank you for your feedback.
I'd noticed that more films were available in 120 but hadn't realized they were cheaper.
I shoot virtually exclusively B&W. I hadn't realized that +/- development would be available only with 120; why is that?
I actually am not doing my own darkroom work, but my lab technician does it all by hand, and he will accommodate my requests for +/- development.
Tom, I considered going with a 501CM but decided that I might wish I'd had the flexibility of the 503CW; do you have any thoughts about that? Do you find that you can hand-hold at some pretty slow shutter speeds?
I also hadn't realized that it was the wedding photographers' switch to digital that resulted in my being able to afford a Hasselblad system! What irony.
Again, my gratitude.