We were given a voucher as a gift and had previously not known about The Secret Spa, which is well named as we encountered a bit of confusion as to how to get into the right bit in order to start our day (we went into the gym first and there was no signs or instructions as to where we should be) however, once we had found ourselves in the right place the staff and facilities were very good. We went on a Tuesday and it was very quiet so no queues to use the gym equipment or any of the spa facilities. Lunch was fresh and tasty and the treatment was very good.
Only criticism (and it's a very small one) is the signage - but having said that they may have explained this in the email they sent beforehand to confirm the booking and I may not have read this.
Brilliant day from arrival to leaving the staff were very attentive but not intrusive. Location and facilities first class. Would certainly recommend to anyone.