The pros: this is a beautiful apartment, bigger than it seems in the pics, and the living room/second bed area is practically a second bedroom. It's in the classic style of Copenhagen apartments, so it makes for an authentic stay. It is tastefully furnished with lovely art, plants, etc (a little different than it looks in the pics). There is a small playground in the building courtyard, but it is suitable for smaller children; if they are small enough to appreciate it, they will not do well on the four flights of stairs. The location is good, near the metro and in the wonderful neighborhood of Østerbro.
The cons: We discovered on checking in that the washing machine was out of commission. Not sure why the owners did not see fit to warn us and the management--hopefully they will communicate better in the future, especially on main selling points like this. There were some minor inconveniences (ex no hand towel in the bathroom) that will hopefully be rectified in the future. The window in the living room has no blackout shade, and it's only dark for like 6 hours a day in Copenhagen in the summer, so not a good place for people who need darkness to sleep (the window is huge, so the parent-hack of covering it with cardboard will not work.)
The management was super responsive and helpful about the washing machine issue. They paid for our laundry and even gave us some extra for the trouble of hauling the laundry up and down stairs. I am entirely satisfied with their response and would definitely book with Apartment in Copenhagen in the future (in fact, I would suggest looking at their website).