Thanks for all the replies--really making me think about what I want to do. Right now, my decision is deferred.

Thanks for the picture of the revamped Nano; it's quite nice looking! I'm fairly average height and inseam (5'8" and 30" inseam), and from what I could find, it seems like the 48C or the 53C Nano could work, but I have no reference to what I would normally ride on a road bike; the only bike I've ridden in my adult life is my Boardwalk and it's what...2 ft standover height.