Actually, I should also mention that I just got a BetterScanning wet/dry film holder for my v750 scanner. So far I've only scanned about 3 negatives, after doing a lot of height-calibration scans (the scanner lovingly came with a transparent colour-chart). I've yet to buy the wet-mounting fluid, I don't suppose I'll use it that often, only for the really really good ones I want to print huge.
But the results i'm getting from Dry Mounting vs the film-holder is already a lot better, but a lot slower and harder with sticky-tape going everywhere.
The thing with the scanners is that the Epson 750 is the best flatbed, it's got coated glass for no reflections but is otherwise similar to the 700. Down from there is the 600 and lower, they've got a much smaller film-area. The 700/750 can scan up to almost an A4-sized transparency, not that I'm going to (god help me if i ever start shooting 8x10). But it gets 24 frames of 135 on a single scan, 6 frames of 6x6, 8 frames of 6x4.5. The 600 and lower only get half that, and nothing wider than 120film (again, don't get into Large Format or you'll go broke). I'm not sure about other brands, I've heard good things about the Nikon Coolscan, but just saw one on ebay for over $5k, don't even think about a Flextight. They're Drum-scanners and a lot better, but you pay for it. No other flatbeds come close to the Epson from what i've heard. Check out here for reviews on lots of scanners.

Developing your own film is a hassle that i just don't want to deal with, I spend more than enough time on my photos as it is without needing to mix chemicals. I'd rather pay my $6.50 a roll and let someone else deal with it. I have considered it though, and the only thing that I could think of is to find someone locally who knows what they're doing, and get instruction, maybe even find a course if you're lucky. B+W is always the easiest, maybe Negs, but afaik Slides are a crapload more complicated to do at home.

And jrw, I think that the 90mm f/3.5 is the normal lens for an RB/RZ 6x7, which was definitely the more studio/professional oriented camera (still, you can get digital backs for them, that rotate like like RB film backs, and not for m645AF and the manual bodies).
Mamiya 645 Manual lenses all started as Sekor 'C', then the newer versions are 'N' (and the occasional L or LS for Leaf-Shuttered), all the new AF lenses are called AF. All the manual ones can be used on Manual and AF cameras, and EOS via a $10 adapter. The AF ones can only be used properly on AF, they will fit on manual bodies and EOS via adapter, but only wide open.
The confusing bit is that most RB/RZ 67 lenses are called Sekor 'Z', but some are also called 'N'. It's easy to tell with it in your hand though, once you know what the mounts look like, and most RB/RZ lenses don't have focussing helicoids because the focus was in the camera (just like Rollei SL66).

As for eye control, yes, it's awesome. But when it came out apparently there were complaints at the time (most by people who didn't realise there was an 'off' switch, much like how people complain about video in dslrs these days), and it wasn't the best with glasses and/or contact lenses (not a problem for me). It only ever made it into the EOS 3 and EOS 5 and maybe another lower model or two, it didn't go into the EOS 1V. there were probably other technical reasons it didn't get put into the 1V or dslrs in general, maybe it mucked with the metering (like red-AF points in the 5D3/1DX)? I dunno, but I love it, and wish my 7D had it.