I lusted after one for years. When it finally came along, it was wonderful, except that it was pretty useless off tripod unless tied to a flash unit in the studio. It was pretty bouncy, but apparently the Bronica version outjumped it, capable of leaping off a table.
The old Rollei TLR was a better hand-held bet outdoors; wish I'd also had the 135mm version of one. I think I have seen a pic of Bert Stern holding one in his studio. I wonder how efficient they were with handling parallax; my pre-Hassy Mamiya C3? TLR with its 180mm was capable of making great images, but using the parallax correction moving red line was a nightmare. It was a very clunky camera.
Unfortunately, I had no uncle with a Hassy, only an old Leica, but his wife had an equally old Rollei that she lent me at a very critical time in my formation. I didn't expect to inherit, and there was no reason I should outrank their own three kids! I wasn't disappointed...
:-)
Rob