Roughly 38 to 97 gear inches is a totally respectable range. I think I could get used to that. FWIW, I tried out a (goofy reclined beach-type) bike yesterday with a Shimano nexus 3 speed at a LBS. Besides that backwards shifter, I thought it was fine. Didn't notice much in the way of "inefficiency," though oddly I found the instant shifting took some getting used to.

Matariki, what do you think about the "noisiness" and "inefficiency" of the S-A five speed? Any of that stuff bother you?