I was there in the end of june, beginning of july with a friend. (Two 30's frenchies). The hotel didn't feel packed and felt very resting and quiet. I'm not even sure to have seen a child there.
Included breakfasts were varied and good.
The only downside for us (which had nothing to do with the hotel at all) was we couldn't really talk/chat/exchange much there as we didn't speak much Deutsch. The waiters and people working there were also mainly more fluent in german than in english. But with a bit of time, we always got understood.
Rooms were clean and cleaning was very discreet. We often went to breakast and when back, the beds were done, towels changed, and bathroom cleaned.