Is there really a lot of hate for the Z31 or is it more like there's a lot of adoration for the prettier Z32? Personally, I've always loved the look of the Z32, but the Z31 is like the homely-looking sister.
Wasnt it a followup and attempt at 'modernizing' the Datsun 240. All the cars of that era were going to the boxy robot look (Corvettes for example). I used to HATE the styling of nearly all 80's cars. Now, some of them are actually half decent looking, and some cars today are actually mimicing the boxy styling again (Example: Camaro).
The Z31... ehhh, almost half decent looking. The old datsuns can look WAY more badass IMO. Id go datsun 240 over z31. Niche market I suppose. If you love 'em, you probably REALLY love 'em. Manimal practically stole these cars, so well worth it.
I dont mind the rims on it, but you are right, some 15" meshies would be killer.