A LOT of good advice here. Let me step in with a consideration I haven't seen yet. Some of these cameras, especially the Mamiya 7 and the Hasselblad, hold their value remarkably well. Meaning, if you buy a Hasselblad and a couple of lenses, it will set you back, but if you don't like it in a year or two YOU CAN SELL IT FOR WHAT YOU PAID FOR IT! That assumes you've taken care of it and the film industry doesn't just disappear overnight (knocking on wood).
I had this experience with a Leica M4 and a few lenses that I recently sold for a bit MORE than what I paid for it when I decided to get a Mamiya 7.
This may also be true of the RZ and RB and others mentioned, but I am not sure. The upshot of course is, go ahead and get the best you can afford and make sure it's one of these that really has been stable in value and you really cannot go wrong. You can try it and then switch if it doesn't work.
When I first started shooting MF, that's what made me go for a Hasselblad. I wish it was 6x7 format bcs I love that aspect ratio, but it is pretty easy to carry around with a few lenses and backs and super flexible. The Mamiya 7 is less flexible but a marvel of sharpness, lightness and ease of use. And if I change my mind and sell them, I'll probably be out very little money.
There's a whole galaxy of wonderful cameras out there, and the great thing about that is somewhere the perfect one is waiting for you. The bad news is, deciding which one can be a challenge. I've been fortunate enough to have picked some real winners, but I've also worked with some that didn't quite meet my expectations (few). One thing nobody's mentioned yet, it may not make any difference to you or anyone else for that matter, but over the years I've developed a real dislike for cameras that rely on batteries. They're expensive, require constant attention, and die at the most inconvienent times. When they die, unless you have a spare, you're screwed. If they only power a built in light meter, that's not so much a problem because most of us can do just fine without one. If, however, the camera need one to function, that's another matter. That's why while I think something like an RZ-67 is a dandy camera, given the choice I'd take the RB-67 every time. No battery with the RB. In fact, I did choose the RB over the RZ for exactly that reason. It's also why that, my Rolleiflex, and my 4X5 field camera are the only ones I use anymore. Totally mechanical camera's, to me anyway, also have more of a Zen appeal and make me feel like I have more control over the picture taking process. Just a thought for whatever it's worth. Cheers.
If close is something you want, RB&RZ both have bellows. That plus extension tubes gets bulky but versatile. Rb's with 120 back & either 127 or 90 are around ~$300. currently. The 50 is excellent but you would want a "C" version with floating elements.
Close stuff pretty much rules out the rangefinder cameras of any brand.
Mamiya RB?RZ are the bulkiest, the GS1 probably the smallest.
The Pentax in my opinion is a non contender. It's pretty awkward(for me) to handle.
When comparing weight in order to consider apples to apples Each camera needs to be set up for use. Someone mentioned earlier a light weight body. What does the back and lens add?
As I'm sure you well know, it's good to handle and preferably shoot cameras before purchasing.
A 4SR44 lasts for several hundred rolls and the <$10 spare will take literally 2cc of space in your bag. The camera gives you maybe 50 rolls of warning before it malfunctions. To avoid that, frankly-zero, level of inconvenience, you end up with unreliable mechanical shutters that need servicing to keep good time, not to mention coupled metering.
Batteries are not any form of drawback. Hell of a lot easier to deal with than keeping your beast fed with film.
Highly amusing treatise on batteries really, and quite the stuff of fiction.
If you are not so keen on a battery powered camera, use a pinhole. Tell me what it cannot do that the RB-67 can, and why. :)
Well thank you all, that was a very informative discussion. I frankly had no idea there were quite so many different options - I mean in a way I knew they existed, but in a way I did not realize how different each medium format solution is! I guess it is the middle format for a reason.
To be completely honest, after reading all this like 3 times, I am tempted to look really good at the 4x5 route for the big stuff. Maybe the best solution would be a 35mm for the quick stuff and 4x5 for the slow stuff. But I will certainly keep this all in mind as I look around and try to handle a few of these bodies and see what they feel like in the hand.
Thank you all very much for your time and sharing your hard earned knowledge!