Mamiya repair techs - RB vs. RZ for reliability/repair-ability?

This comes up from time to time, but from the user/owner perspective it seems to be pretty anecdotal. Is there a reliability edge to one system over the other? In my (anecdotal) experience, it seems RB lenses are really reaching a "needs service" era, but it also seems a proper CLA means years/decades of life, and usually no parts are needed? Where are RZs failing the most?

Maybe we can get u/Brcamera to pipe in, or any other actual repair techs (vs. the "I once cleaned a shutter with q-tips" experience?)