The staff are outstanding: friendly, helpful and attentive. The spa was very pleasant, while the treatments and therapists are excellent. Overall, though, I was a bit disappointed with several aspects of the holiday.
First of all, the pictures are somewhat misleading. Coral Bay is a deep "U" shape. The base of the "U" is a public beach, incredibly crowded and, at times, very noisy with music etc. The Thalassa is half-way along, perched on top of, one of the arms of the "U", so the view is of the hotels on the opposite side of the bay's "arm", the public beach (to your left) and then the sea off to the right. The bay is very busy, with tour boats (loud music intermittently and annoying, "Hi-De-Hi" type MC's giving commentary) - very intrusive, but it was intermittent. I chose the hotel on the basis of the "adults only" policy, and the pictures/description that it was in a secluded location. It's certainly not a party spot, but solitude was what I was after. Make your own choice based on that caveat.
Secondly, ALL meals are buffet-style. Food was pleasant (not great), varied and plentiful, but I missed having proper restaurant service (no one used the abandoned a la carte room, at the opposite end of the hotel).
Rooms: pretty basic, hard/cheap mattresses, thin pillows. Poor TV reception on satellite.
Grounds - very small, just the pool and two terraces.
If you want just the sun, the pool and to lounge about, it's a decent place to choose.