Thanks! I do a very flat scan to start, being sure not to clip any highlights or shadows, and then tweak in Lightroom as necessary.
A wise move, indeed.
Personally, I'd be careful comparing preferences in 135 to 6x6, because of the widely different aspect ratio. Keep in mind that the vertical angle of view on an 80mm Bronica lens is the equivalent of the angle of view of approximately a 31mm lens in 135 format or something to that effect. Moreover, many of the photographs I see online feel cluttered to me and usually need to get more intimate with the subject, not farther away, so I'm always hesitant to recommend wide angles. I personally don't own anything wider than the 80mm at the moment, anyway
At any rate, with regard to 50mm lenses, it is the SQ-A that you own, right? There is no 50mm f/2.8 in the SQ lineup, only f/3.5; if it is an f/2.8, it is meant for the ETR series. The thing to keep in mind with the 50mm f/3.5 for the SQ is that the S lens has 67mm filter thread, while I believe the PS lens has a 72mm thread.
I had to go back to OS X 10.8.5, because a few of the programmes I require for my PhD weren't compatible with Mavericks, but I've never had any difficulty with my combination of Epson scanner, OS X, and Vuescan at any point.