We spent in Hinterglemm our winter holiday, during the new Year and we really enjoyed those 7 days. Everything was brand new - the new hotel was launched only one week before, very nice decorated, clean and warm atmosphere. The restaurant services were really very good, nice food and I would say too much in terms of quantity... The spa facilities of the hotel are also good, only the employees need to be trained more as we had one minor incident with the lady who was heading up the spa: eventhough we got in our offer that the kids have unlimited access to the pool, one day she came at 5 pm saying that the kids are not allowed after that time. Anyway, we made a complaint at the reception and she did not appear afterwards, so it would be worthwhile to check the hotel policy regarding the kids before booking... Talking about spa, during our stay they used to have some problems with the showers (did not work after the first day, so you had to go to the other part of the spa to take your shower before pool etc) and also the exterior heated pool was not ready.
Hinterglemm is one of the best resorts in Austria, with very good slopes, transport facilities and ski school for kids, so we decided to repeat this experience in the next years, too.
As a general impression, the hotel deserves four stars and was a nice experience for us.