the big difference...shoot.... one is Chrome the other is polished.
polish doesnt have that "bling" status that Chrome can produce. Chrome looks nice on almost every vehicle as long as it is over done (lots of spokes, too big of rim, etc..)
chrome costs more and u cant do it yourself.
Since you are asking this ?, post a pic of the rims that u are deciding on polishing or chroming and make a poll. That is, if u are thinking about chromin or polishin rims