i run drag DR21's on my FitS. they look great, average weight.
im running them in the winter right now (caked in salt) and initially had
some very minor pitting on the lip which appears to be from some
salt/gravel i must've hit. it's only on the front wheels and none on
the back.
i was a little worried at first but has not worsened. ive been using spray
wax (Prima Hydro) every 10 days or so.
my recommendation: wash regulary and keep them waxed.