Since they're both discontinued systems it's tough to recommend either one. I was always partial to the Mamiyas and I think they are probably a better investment if you ever plan to buy a digital back. On the other hand, since we started this site I couldn't help but notice that the Bronica system was the only one with perfect reviews - even after the manufacturer discontinued support.

Do you have a preference? What was your previous system? Do you have any intention of investing in a digital back in the future?