Greg;
Thanks so much for those mf links. The articles therein are some of the most interesting and comprehensive mf articles I've ever read.
I'm in a similar situations to the OP David. Been thinking about mf on and off for awhile. I'm drawn to the Mamiya 7 but I'm so accustomed to slr's, a rangefinder might be a problem. I think (with the help of those links) I've narrowed my choices down to the 645 format, probably the Mamiya 645 Pro. They are just so damn cheap these days!!
My biggest challenge will be to convince my wife I need another camera......but one step at a time
Thanks again to all, great thread, lots of useful information!
Best
Paul