I find the SS wheels on my +8 easier to clean than the alloys on the other cars.
My advice would be to make your decision on looks, you would certainly need to be a more sensitive driver than me to spot any difference in driving.
The comment on width is is worth noting, if the new cars are the same width alloys or wires, then that would swing the argument back to wires for me.
(If you do a search you will find more info on this subject, with the little-enders never going to agree with big-enders - so-to-speak)