We stayed at Petra's place for two nights and had a lovely time in Prague. The location is brilliant - very easy to walk to all the sites but not central and noisy.
Petra had great communication before our stay and gave us lots of tips and recommendations which was nice.
Some points I would mention is that the toilet is outside on a shared balcony, although the toilet is a private one. It was quite smelly and didn't seem particularly clean. It was a bit like being in a cupboard.
I felt the apartment wasn't quite as light and clean as it looked in the photos and the windows did not seem very secure.
Otherwise we had a great time in Prague.