i have had mamiya 67 RB and RZ systems and currently a M645AFD2 w/55,80,150 lenses and i am really happy, i am shooting with a P25, FF 22MP back. that price sounds good, and comparable to a phase one system w/P1 P30 31mm cropped sensor.
i think their lenses are under rated, sure Hassy is supposed to be the sh*t but others are extremely good, even better, like fuginon/fugi. some people say the mamiya lenses arent built that well but i dont have a problem. i like that almost all of there lenses take 58mm filters and the next common size is 77mm, (like my canons).
i like the AFD2 body too, im a fan. my only complaint, AF is ok at best, i wish the AF points were a bit more precise, not more points, just smaller ones. its more like a MF system which a quick focus (aka AF), it makes me shoot slower (and the back can only go 1 frame in 2 secs), but my keeper rate is really high.
capture one 4.5 is great in getting rid of the slight CA that the lenses occasionally have, but by 2 stops down from max fstop most of the effect is gone.
its a time to use what you have and enjoy it not to get new toys just cuz you can...