We lucked out with a preschool near a University. Against all odds more than half of the other students were at least MG. At the same time, I caution you that the value of the experience was largely the result of the teachers, and their attitudes. In our case, the head teacher brought in articles on giftedness to the first parent/teacher conference. She was amazing, but she was not the teacher when we signed up for the school. She was the replacement. Teachers change.
The next preschool we dealt with had a solid reputation, and was very organized, clean and had great resources. Unfortunately, along with organization and structure came an unwillingess to accept variances between children. That one was a multi-age situation, and it didn't work for us. My children tolerated it, at best.
The stated educational philosophy was very similar at both schools. Grinity is right, try to find the least-bad option. I'd add to make your best decision, but understand that things change as often as the head teacher changes.
