If you read this, then you are already planning to go to Copenhagen. I think you won't regret it, it is a really nice city (and Danemark is a very nice country with nice people)

In Erik's apartment, I stayed in a room on the front part of the building and I liked it because :
- the bed was good, there was a small desk (useful to read a map, write postcards, ...), wireless internet access;
- the room is quiet and has a very nice view on the lakes (the ones behind the planetarium);
- the apartment is very well located : you won't need more than 10 minutes walk from the central train station from Copenhagen to this apartment. And the station is next to Tivolis gardens, the stroget, many interesting places in the town center. And in less than ten minutes, you can also reach a metro station or many bus stops to get to other places. Better location would be hard to find;
- Erik is a good host: he makes you feal confortable / at home, gives you really good informations about the city, places to see (he gave me a map of the city, very useful if you get there without any), groceries nearby (there are many), ... Being his guest is a pleasure.

A few more things :
- there is a "city bike" station near the planetarium, but most of the time there was no bikes. But from time to time you can get one and the city is really pleasant cycling ;
- if you are a jogger, then the lakes in front of the apartment is a very good place to run (many joggers every morning of my stay, nice place to run).

The only thing that should dissuade you to go to Erik's place: if you have problems climbing stairs (the apartment is on fourth floor)