I've played with all manner of MF cameras in the Mamiya stable, and then went to Hasselblad. With the exception of the Mamiya 6MF (which I sold in the end last month) none of them handled like a Hasselblad. IMHO, Hasselblad is the best system out there. The longevity and lineage is and has always been there.
Sure I got distracted with Mamiya 645 on many occasions, and I am not dis'ing that particular marque.... ( I never learn). Yet, I always come back to the square format, specifically Hasselblad.I had a brief affection for the Mamiya 6 like said earlier, and those RF lenses trounced the ziess versions no if's and's or but's. ( I know I'll get 'flak' for that) However, the M6 rangefinder was not to be for me. I like a ground glass, and while it served me for 10 years, when I got another Hasselblad body, the M6 got left at home more often than not.
While I've handeled the RZ at various stores before.... I was just not struck on it's heft, and general awkwardness to use... Maybe it was me, and again personal preference. The Blad is just more intuitive, but again that comes down to familiarity.
YMMV and you have to find what best suits you. If I could do this over again, I would pick Hasselblad as the perfect all round #1 choice and you only have to bleed once when you purchase into the system. I chose to do it a few times

The last time was to get a body with focal plane shutter for using funky lenses and not because I'd wandered off course again!!!