I used a ETRSii (I think) before, with rapid winder, 3 different lenses and different backs (135/120).
Fantastic lenses, and an equally good, solid body, but you have to be aware that since the political/business side of Bronica has burst, down the road, finding parts and service may be increasingly difficult, and in time, impossible. If the same were to happen to Mamiya, finding parts/service would not be so difficult as there are a much higher volume of mamyia gear floating around at any given time.
It's a pity, really, as I feel that the Zenzanon lenses were on par with Hassie's Zeiss, and in some tests, a wee bit superior (for the 6x6 lenses).
Also, since the economic situation affecting Bronica, most unfortunately, the value of Bronica equipment has generally fallen quite sharply as opposed to say, Mamiya.
As much I love Bronica, I would offer the (at the moment) healthier adivise of plunking your cash for a Mamiya.
BTW, I have also owned and used Mamiya's 645 equipment. Only thing I never liked about it were the focal plane shutters. Nothing else. Thousands of professionals around the world make their living (and riches) with Mamiyas.
I still feel sad for the Zenzanons (and manual Zuikos though). Some of them were real classics that would give Zeiss a run for their money, and beat them, ever so slightly.