I've got one of the originals (first gen). I've owned it for a couple decades so here's my take on it.
It's huge, it's heavy. How's your back?
It's annoying to deal with power issues, then annoying some more to deal with a power issue in the old filmbacks. You'll buy the AA holder, it's dumb expensive, and the camera will eat the AA's for lunch. You'll learn to take apart the film back to solder a new 1/2 AA lithium battery into place, you'll need to buy a soldering iron and learn to solder. You'll need to buy fancy screwdrivers to open up the back. You'll do it again because you did a crappy job soldering. Next time don't be so cheap and buy the battery with the axial leads.
You buy lenses from Japan that might work but are too far away to return. You want a couple lenses to be able to switch, but they're BIG too and so you'll probably only take one with you and leave the rest in the car. It's made for the studio but you drag it's heavy, oversized self to the field anyway. You'll buy a few bags trying to sort out how to carry the thing into the field. Your arm hurts from wielding the thing on to the tripod - and the tripod must be a monster itself to support that monster camera.
You'll want a set of compendium bellows, they require adapters for each size of lens. It's impossible to find the adapters, when you do they are expensive.
It takes a proprietary release... one is a meter long, the other is 15 meters long. The short one is too long, the long one is too short.
You'll want the extensions for macro, so you'll need the extended bellows. You'll need to get the wide angle bellows too. You'll likely get the two different wide angle bellows. Switching bellows is finicky. They have lens movements, if you collapse the bellows and don't reset the movements you'll wrinkle the bellows. They don't make new bellows.
You'll get the Waist Level finder. Then put it on a tripod, then the tripod will be up and you'll need a chair to stand on to use it, so you'll buy the angle finder. The Angle Finder is huge and has glass in it, you'll probably want to leave it in the car too.
It doesn't have a meter. You'll buy a handheld, they're expensive. They're one more thing you'll get to take along with the oversized camera in your oversized bag/backpack. Actually they can have a meter.. in another finder, that's big. Actually the camera does have a meter, but not a "here's a good Fstop and Shutter selection" - they have a meter that will beep at you and tell you that your exposure is more than 2 stops wrong, but only after you take the picture. ("Right, that's bad. Okay, important safety tip. Thanks, Egon.")
You'll think you want to use it without a tripod. How's your back? If you buy a gen 1 or 2, you'll get to buy an oversized thing that looks like this:
Which is the picture in the Oxford English Unabridged Dictionary of the English Language Volume 1 under the word
Asinine (adj): ex: Providing something like this as a camera strap for a camera that is intended to be used in the studio is
asinine.
You get 9 negatives from a 120 roll. Process with stainless reels like you should. Don't be a putz and learn to thread the thing. Process each film in it's own stainless tank. Yes I know it's only 9 exposures and you shot 4 reels and you have a 4 reel tank. You're going to screw up all four if you do it that way, so don't.
Buy the correct Negative sleeves to fit them. It's the one no one carries. 3x3, up and down not 2x4 horizontally. You want the right one other wise you get 8 on the standard 120 page and you have to put a single on another page. Which is dumb, putting a single into a negative carrier is hard too.
You'll get to buy a negative carrier. Film photography is about using an enlarger. (piss off you scanner people!) They don't make a 6x8. Actually it's not a 6x8. It's a 56mmX76mm. They don't make a 6x8 or a 56mmx76mm carrier. You'll get to buy a 6x7 carrier and a file. And maybe borrow a vice, and some calipers to measure. Start filing, have a beverage, keep filing. Do. Not. File. Too. Much. Don't file too little either, you want as much negative as your sore back can provide you with.
The negative is big. For the love of all that is holy, do not be cheap and print small. It's a go Big or Go Home situation. Buy 11x14's at least, or for you Pommie's 14x11". Fiber dammit, put that plastic-fantastic RC stuff away. Are you a heathen boy? Don't use that 90mm enlarging lens (tell me you weren't thinking of trying the 75mm!) . Use the 105mm or you'll loose a little on the edges. Go buy a 105mm enlarging lens. Don't cheap out buying one from a Slavic country - even now they're made from compressed communism and the tears of the oppressed. It's WEST Germany or something from those Rising Sun guys. If you're trying to keep it real.... search out a Fuji enlarging lens. EBC Fujinon EX 105mm 1:5.6 when you get tired of it - send it to me I've been wanting to try one out.
Print well. The 56x76mm is really just as they tell you. It's damn perfect for the 11x14". Feel smug about it, Your back earned it. Pull the fiber slowly and carefully from each bath. Rinse well with water from artisanal wells blessed by the Pope or that guy from Nepal or is it Tibet? Dry on a screen, overnight, none of that hurried heat crap.
Mount, Matte that print on Ragboard. Show it to your Chiropractor.
Really... It's good kit. The pitfalls of the system are well documented everywhere a keyboard can get you. I just thought it should be collected in one place. In my opinion, which ain't much, it will equal or better every negative produced by any other maker.
You folks have socialized health care... are they better with backs than with teeth in England these days?
So, the reason for looking only at the III model is that I just don't want to worry about batteries. Been there with the Rollei 6008, did the refurb, bought the li-on and all that so if I ever buy another camera that uses batteries it will be throwaways, so the III will do with the CR123 and CR2 which is great as I already have cameras that use those.