My boyfriend and I stayed at Kate's for a weekend in Amsterdam, and we definitely recommend the place! It is very central, with all the tourist attractions reachable on foot in max 20 minutes, and surrounded by restaurants and bars.
Plus, the team managing the room was very kind in waiting for us and giving us tips on how to get there in the adverse weather conditions.
Only downside, 5 flights of quite steep staircases, but they gave extra character to the place :)