All the people manning the reception were very welcoming, helpful and polite. Managed to get upgraded from a studio to a one-bed flat hence the place was very spacious. Flat was comfortable and warm. The underfloor heating in the bathroom was a nice touch. Metro and tram stop are near (less than a 5-minute walk). Tram 22 takes you directly to the castle. There is a convenience shop called zabka opposite the building. Otherwise a bigger (and cheaper) tesco is about a 5-minute walk away.
Overall we enjoyed our 3 nights in prague and at the flat.