I actually bought a Mamiya 645 before the Hassy. I can’t remember the details, but I returned it because of some electronics defect. The Hassy has been reliable. I know there was a period when they were shit due to some ownership change, but mine was not from that period.
The waist level finder and square format makes you approach each frame with a very different mindset. It is much more contemplative, slower, more composed way of doing things. For me, eye-level viewfinders and auto exposure encourage a faster, snap-shooting style. I like the Hassy approach a lot. If you get a chance, try it for awhile, it is very different!