We had a great stay at the flat and really enjoyed our time in Copenhagen. If you don't like walking that much the accomodation might be a little far from the city center/train station but it depends on what you're used to. It's about 30 minutes to the main station which was just fine for us. It's definately a beautiful flat, but there were two little "issues" that I don't consider as too disturbing: 1. the kitchen wasn't super clean and we didn't want to use some of the stuff because of that and 2. (this might be because we came in end of december) there was so much stuff on the balcony that you couldn't really step outside, which of course we jsut put away to get on there but it was still a bit uncomfortable out there because of that.
I still want to say that I would def recommend it and stay there again!