Our stay in the apartment was great! It's a building with a 24h reception and with very kind people to help us! In the first day, the WiFi was not working properly and when I went down to ask about it, Katya (a very helpful and kind girl) told me they were checking and fixing it and to apologize for it she gave me a bar of chocolate!!!
The apartment is really big and veeery comfortable! And it's 5 steps from the metro station! Very well located!
In our last day, we could left our luggage in the luggage room while we were in the city before our flight that was later that day.
A great experience and we'll stay there again when we're back to Prague!