It depends on what the person is a perfectionistic about. Perfectionists are not trying to be perfect in every area of their lives. So a man who's extremely careful about getting his figures exact on his reports may have a desk that looks like a bomb has gone off. Or a woman who thinks her house needs to be in perfect order at all times may have a car that hasn't been washed in six months. If the person is perfectionistic in sexual areas, generally it does not make a better lover.
Perfectionists tend to worry about their areas of perfectionism.
They try very hard to get everything just right. Most times, this results in some anxiety while they try to get it all perfect. Anxiety and sex don't go well together. The best sexual partners are relaxed. They're not constantly worried about whether they're doing it right, whether they're measuring up to the other person's expectations, whether they look perfect in the bikini underwear that their spouse got them as a gift, and so on.