We booked two nights for a family of five. The address where you need to attend given on the internet is not where the apartments are. they are a short walk down the road. I was pleasantly surprised. the apartment had three bedrooms and was quite spacious (except for the kitchen). We enjoyed Prague so much we asked to stay for another night, which they allowed us to do.
The location is its best feature as you are only a short walk from the Charles Bridge. I recommend it and would stay there again in a family group.