We stayed here for 5 nights on a family holiday (with 2 young kids) during August. The hotel is within an old brewery, which makes for a very strange shape and bizarre internals. The room we got was large, but sparse with virtually no furniture and huge open space in the middle. Having seen some of the other rooms, ours seem one of the more dated. Despite the size of the room, the bathroom was very cramped and the shower would spray everywhere.
The breakfast buffet overall was very poor, with a limited selection and generally average dishes. Having been around Europe for 3 weeks, this was easily the worst buffet breakfast we had on our trip (contrary to many reviews we read about the hotel). Unfortunately the hotel also constantly smelt of fish, as I believe they served this regularly in the ground floor restaurant to large tour groups.
One the plus side however was the location. The surrounding area has a great selection of bars and really nice restaurants to choose from. Its also easily walkable, and doesn't take long to reach Gamla Stan by each walking, subway or bus. There is a really good playground nearby too if you have young kids.
If we came to Stockholm again ( I hope we do, its an awesome city), we would be hard pressed to stay here again, despite decent location.