I stayed in Katkas place for a long weekend trip with my boyfriend and we had a super amazing time in Prague! We arrived quite late and Katka was waiting for us in the apartment to give us the Key. Her welcome was very warm and she even took time to explain stuff about our living area and things to see in Prague, gave us a map and other valuable information for finding our way around in the city.
The apartment is exactly as described (absolutely beautiful) and you can find anything you'll need. We weren't missing a thing! It's a safe neighbourhood and you can easily walk into old town or the city centre - it's a nice stroll. Also the train is like 2 minutes from the apartment and you will only take 5-10 minutes into the centre if you catch one (they are running very often).
All in all I could not give any other advice than: book it! :) I strongly recommend Katka as a host and her apartment as a brilliant place to stay.