We stayed for 3 nights, 5 adults (with our 3 big kids).
The apartment is very comfortable, in a very good location in the old town but in a very quiet street. Ondrej was very responsive, helped us get to the apartment from the airport late at night, and patiently explained everything we needed to know about the apartment. The third bed is on a wooden balcony inside the second bedroom, and my son could not stand there. The kitchen is fully equipped and very comfortable.