Gustav's mansard is right in the city centre and therefore ideally located for sightseeing. The mansard itself is very spacious and very clean and there are great views from the rooftop windows. The furnishing of the mansard is quite sparse. It did, however, not bother us since we did not spend that much time in the mansard apart from sleeping. The beds and showers are ok.
Gustavs himself was kind and helpful and meeting us at the mansard right of the plane. The airport is not more than 15 minutes away from the apartment by taxi and the taxis are very reasonable. The mansard is accessed through three big staircases and one smaller one at the top. The stairs are broad and easy to navigate. However, be aware that it might be quite a jog with a heavy suitcase. At night the mansard is very peaceful which is delightful since the location is so close to the city centre. Plenty of restaurants and cafes quite close and most sighs easily walked to from the mansard.