Dan, I totally agree - I shoot macro mostly with my Canon and a Canon MP-E. And some with my Hassy and some tubes. I wouldn't get my dad a view camera (that's a side project that came out of this thread that I am interested in myself). He used to own a Mamiya 645 (don't know which model), but apparently traded it in for a Pentax some time ago. But that one spends more time at the repair shop than in his photo bag.
Tough choices. In any case, I picked up that poor Mamiya 120 macro for under $200 I found. Looks clean so far. Maybe I'll just get a body for that and see how it handles. My husband is fearing the worst - Antje venturing into yet another camera system.