Stephan was very welcoming and made me feel comfortable in his apartment, explaining all the important stuff such as how to operate a Copenhagen-style shower - which is basically an attachment fitted to the tap on the sink in the small toilet. This is a bit fiddly but I managed OK.
The apartment is in a great area: Islands Brygge, which is near the water and close to the city centre. Apartment is about five minutes' walk from the Metro (handy for airport). Area is lively but flat is in a quiet spot - it's on a leafy courtyard adjoining a busy street (which has shops where one can buy food and other requisites, with bars and cafes aplenty nearby).
My only noise issue of note was the sound of kids running around upstairs quite early in the morning.
The room in question is Stephan's front lounge, which is spacious and has one wall full of his books, DVDs, etc. There is also a stand-up-style piano in one corner should you feel musically inclined. Bed is a basic couch in one corner which can fold out and make a double, but which I slept on top of as a single after taking off the cushions. Sheets, pillows etc were all provided (ditto towel; toiletries are provided gratis but I brought my own) and were very clean. Bed was long enough for me (6ft or 184cm) and I slept well. I didn't use the small kitchen but it looked just fine. Stephan was very flexible re logistics, letting me leave my luggage in his place while I roamed the city the next morning and afternoon.
To sum up, I can certainly recommend Stephan's place if you need somewhere to stay in Copenhagen.