I have a pearl white MS and I really like it. While driving, it's hard to tell the difference between flat and pearl white. I pass lots of white MSs on the road, and rarely can I tell in passing if they're my color or not; only when parked.
I'll stick with white because I live on a very dusty California gravel road. It hides the dirt best and looks nice and contrast-y against the black nosecone and roof. My wife may have other ideas, and it's her car, so we'll see if that's how it works out.