Our stay in the apartment of Lars was very pleasant. The apartment is in a nice area near the centre, but also near other cool neighbourhoods. There are some good bars just around the corner. Lars has a lot of books and guides of Copenhagen in his apartment to help you sort out what to do!
The apartment has everything you need (oven, stove, wifi, washing machine, good musicplayer / audiosystem, good coffee and tea etc.). It has a nice atmosphere and has several cool souvenirs from different countries. The only (little) downside is the bathroom which is pretty tiny. And make sure your bags are not too heavy, you will have to carry them to the fifth floor ;).

Overall: great place to stay!