Have visited Cedar Falls a few times but wouldn't really recommend it highly - it's the nearest large spa to where I live which is why I have been more than once! When I last visited the gym was looking very tatty. I was given the wrong massage and when I queried it, the therapist said she didn't know how to do the one I'd requested! My friend was told she couldn't have a particular facial (which she has on a regular basis in London) because she was diabetic.. eventually they agreed to do it but with poor grace.
Food was okay but on my last visit there was a power cut and so there was no hot food available.
The setting is gorgeous but I got the feeling that the staff, while pleasant enough, were just going through the motions and we, the clients, were on a bit of a conveyor belt.
Have heard on the grapevine that some of the therapists call it 'Seedy Falls' which is a bit damning.