First of all, Marina and Vlad were amazingly friendly and welcoming at the moment we arrived to the apartment. They recommended great (and cheap!) places to go eat, good places to exchange money and even supermarkets, all close to the apartment and even left documents in many languages with instructions on how to use the appliances and with directions to the places they recommended, so every doubt was left pretty clear, but in the end they were super helpful with any extra questions we had.
It was incredibly comfortable to stay there. The apartment was perfectly clean, organized and fully equipped with everything a normal house needs, they had literally everything we needed except food. The bedroom, kitchen and bathroom were just as big and tidy as they look in the pictures.
The area around the apartment is very quiet and in the park nearby (the one that has the metro station) there is a little farmers market some days (which we loved) and there is a tower with a view to the whole city like two or three blocks away. Also, the metro line is the same as the stations to the main tourist areas of the city, so it's really easy to go there and be back in short amounts of time.
This is truly an amazing place to stay when going to Prague. We'd recommend it to anyone.