I booked via the call center and the representative spoke excellent English. My Spanish is less than basic, so this was a big plus. My reservation was for one of their "special" hours, which are discounted. I opted for the baths + a double massage (30 minutes).
I enjoyed the atmosphere and the pools were very relaxing. Although, some customers really do need to learn to read the signs about being quiet!
I opted out of the coldest pool, since it was so cold outside. The massage was excellent. In fact, I fell asleep!
The lighting is quite dim, but don't take this as a negative. Arab baths have been around a lot longer than electricity. In ancient times the only light came from the "holes" in the ceiling!
If you are in Granada, or one of the other cities where there is a branch, don't hesitate to reserve a session. You won't be disappointed.