If your priority is location, this is perfect place. Everything (except Prague castle) is so close from the apartment, and I did not use any bus or tram because I did not need to walk more than 10 minutes ever.
However it is very noisy at night with people shouting and booing until 3 am, and I woke up at least three times when I was sleeping.
Petr seemed to be a little bit busy but I could see he was doing his best to be a responsive host.
The building is a bit old, once the electricity was gone and some lights did not come back until we checked out. Also mind that there is no elevator and the stairs are quite high.
Overall, it was a pleasant stay with a great location.