First off... you need to pick up the keys from a place that is about 20 minutes away. And if you do not have your own car, then probably longer.
When we finally got to the place, we could not get in with the keys that were provided. After some back and forth phone calls to the "reception" we were told that a cleaning lady locked the door incorrectly, and that they would send a technician to open the door. The technician arrived in the time that was promised (~25 minutes), and gave us an additional key that was not given to us before that opened the doors. So, more than 2 hours after we first arrived, we were finally in our room.
The rooms were fairly spacious, and well maintained. Not all then beds were completely made, which was OK for us since there were fewer people than the number of beds in the place. The whole apartment had a distinct smoke smell, probably from the fabric present.
For those of you who drive, parking is horrendous. The closest public parking is about a 20 minute walk.
Additional note... you better not need extra towels. You need to pick them up from the reception (which is about 25 mins away), or they will be delivered for 15 euros.
Overall, we stayed at 2 other places in Prague during our visit, and this place was the WORST. If you have another option, dont stay here.