This is a great place to stay! We have stayed in this flat twice and have been satisfied both times. They are very quick to respond to any questions or concerns you may have, and the flat is comfortable and has everything you would need.
My only bit of advice... If you are a light sleeper and are visiting during warmer weather, you may want to stay somewhere a little farther away from the public transit. Although it is unbelievable convenient to have a tram stop right outside your door, and it can be a little noisy during the night/early morning.
Otherwise, it is a nice flat with a home-like feel :)