A friend and I stayed at Sebastian's for 4 months while working in Copenhagen. The apartment was great and the long term rental went really smooth.
Østebro is a wonderful neighborhood to stay. There are lots of young familes and its generally pretty quite. Though its fairly residential, its still really close to a lot of great urban ammenities (bars, shops, restaurants, bakeries).
By far the best apartment feature was the HEATED bathroom floor! Its hard to have to go back to the icy-cold rush of generic bathroom floors :)
Overall a great experience, Sebastian was an ideal host. Defintely recommend!