I enjoyed the atmosphere of the spa - felt like I was in Thailand, rather than central London. For me, the neck and back massage was too firm. I did have to ask therapist several times to be more gentle - I would talk to them at the start if you book this. I could hear staff talking in the neighbouring room. Overall I would describe as invigorating rather than relaxing.
It was a relaxing experience, very quiet and tranquil. The facilities were small, we had to share lockers and there was one toilet and one shower only.
The ambience was beautiful. The masseaus was gentle and worked hard and getting rid of the tension in my shoulders. The room for the treatment felt big and airy. It was very enjoyable.