one thing that's nice too is the availability of multiple formats. with the GX680III(I know for sure) that you can get adapters for the backs that can be anywhere from 6x4.5 to 6x8. that means 6x6 and 6x7 in addition to the 645 and 6x8. very handy. I know of a few people that use these cameras, with film and digital backs for architecture and some food(on location) photography. The movements help keep the lines straight(the 50mm however CANNOT be moved more than a few mm due to vignetting), but the 65mm is generally fine enough for most WA shots. nice to have the winder built into the body too
. lots of bellows extension for close-up macro stuff. the III
s version has
no movements(swing, shift, tilt), but takes the same lenses and bellows/shades, etc... just no movements, which you might find yourself using quite a bit.
If I were to do it over again, I'd have gone with a gx680III instead of my RZ system, mostly for the movements(think landscapes and some food, some architecural). the lenses are superb however. as good if not better than Zeiss glass IMO. higher in contrast and a little more saturation out of them, but terrific throughout the entire lineup.
the downsides though from what I've found: 1. Weight: this mother's a heavy S.O.B.! heavier IMO than most 4x5 field cameras with 2-3 lenses. You might want to look at getting a small-ish 4x5 with a 6x9 back or something, so you get FULL front and back movements, lenses would be comparable(if you get good 4x5 ones that is) in both price and resolution. and you get the ability to shoot 4x5 if you want to as well, all in the same camera.
just sayin'
-Dan