Well, one thing is clear: there are many people out there who like what they are using for 6X9 format photography, and they are using quite a variety of cameras. For purposes of full disclosure, this won't be my first medium format camera, and I own a Perkeo II, so I know how good Color Skopar lenses on folders can be (I also have several Vito line 35mm cameras with the Skopar lenses, and I like their contrast characteristics, but I'm not sure I can afford a Bessa). I've now done some research on 2X3 Graphics, and getting one of those would probably be a step forward for me because I do not have any cameras with perspective controls. But I also like to shoot in vertical format, too, and a field or press camera would not fit that habit. Medalist owners seem to love them or hate them, and the vertical format shooting might not work out so well with those heavy cameras, either. I looked at Mamiya 23 cameras on ebay and they seem to go for a fair amount, but the ability to change lenses is attractive, and I have a lot of respect for Mamiya optics.
Yikes, this is difficult. I think I am still leaning toward a folder with a four element lens, but I would like one that either has a rangefinder or can take an auxiliary rangefinder. I have a Voigtlander auxiliary rangefinder, but apparently they can get in the way of the left side shutter buttons on Ikontas and clones. BTW, I also have one of the Audacity iPhone shutter speed testing rigs. I appreciate all the advice here, apug is great.