I think it all depends on the vehicle. Some look great in flat paint, others definitely need some polish.

The stragnest on I have seen was a 40-somehting Chevy, flat black. I even asked the guy if it was the final paint and he said yes. Why was this so strange to me? ALL the chrome was restored and higly polished. That just isn't right. If you are taking the time to redo all the chrome, then it needs "shiny" paint as well.