Katja's place is beautiful, small and cozy with a balcony perfectly suited for morning coffee or sunset dinner. We had a lovely time there. It is worth mentioning that the apartment is close (in walking distance) to the center of the town, and to a lot of famous landmarks.
As for the city itself, Katja suggested a few places to visit and we followed her suggestions - best idea ever. We had managed to see a lot of beautiful places (throughout the city) in 4 days that we spent in Copenhagen. Also, Katja's recommendations included the list of nice places to eat (and we tried it all! :) )
We would definitely recommend Katja as a host and her apartment as a perfect place to stay during your visit to Copenhagen.