My 3 kids are currently at Dolphin and we are very happy with the schooI. As I said recently on another thread, I think that Dolphin has the right mix of good academics and teaching kids empathy. The small class sizes allow the kids to gain confidence particularly if they're shy, which my older 2 are.
The staff turnover is low and they are all committed and enthusiastic, which makes for a positive atmosphere. The head is a strong leader and clearly knows how to run a school well. She also has a good senior team around her who are all very friendly and approachable, and want to solve any issues with you rather than fobbing you off.
I have no comment on BP as we're not in the catchment.
Do PM if you have more questions. Good luck!