Katka’s apartment is perfectly located for exploring Prague. Trans and Metro on the doorstep, lots of things to do and see within a few minutes walk.
The apartment is one the first floor (or second if you’re American) and faces in internal courtyard. It is very quiet at night and warm and cozy. I’d stay there again if returning to Prague.
One thing I would recommend is to book a Taste of Prague tour. You’ll learn so much more about the city and they start the tours about 5 minutes walk away.