Amazing and accomplished teachers (many are former soloists/principals from the National Ballet), wonderful pianists, and lovely, spacious studios (this is where the National Ballet practices).
Really great atmosphere in the studio. Professional quality teaching, yet still laid-back and welcoming to anyone. In the evening intermediate ballet classes, there are aspiring young dancers (often in town for auditions or summer workshops), professional dancers, and recreational dancers (from ages 13 to 80... I'm serious) all taking class together. It's a lot of fun and not competitive at all.
You can pay-as-you-go or buy a card of 5/10/20 classes.