I went to Bea and she was fantastic. They are on the steep side but there are only 3, sometimes 4, people in the class and Bea concentrates on each person in turn.
I've moved out of town now and am pregnant with baby number 2 and I would love to be able to go back to Bea's classes. Plus she's really lovely, down to earth and not to floaty and tends to attract other nice people to the classes.
Good luck.