We stayed in this flat for 4 nights.
The best about this flat: Sarah and Manous were very friendly and responsive. The flat has a great location in the old part of Prague. It was very clean, and was spacious. It has a lift so it's very easy to go up to the flat.
The less good:
The kitchen was not well provided for - so it was very difficult to cook. We had to ask for some knives, oven mitten and some basic items to cook, which Manous provided very quickly. The basics were just not there.
The bed was sunken and mattress was not very comfortable. Also, in the evening, the flat often ran out of hot water.
Overall, we would recommend the flat if you plan to be out most of the time and not cook at home.