Only had one car with one, and I used it a couple times a year, mostly in spring when the weather had a sudden warm spell, and it'd be nice to crack. Most of the time I had the shade pulled over it so I wouldn't have sun on my head. Leaked water a couple times too. In the end a sunroof is probably going to be a disqualifier for future purchases. I don't hate them, they have their moments, but they really don't serve a good purpose for me.
My wife hates them though, and won't have anything to do with them. We're both a/c people though, rarely drive with the windows down.