Amalie and Mads' duplex is an ideal place to experience Copenhagen! Their flat is cosy and very bright. The only minus side was the bedding: for 5 adults (in this case, males), it was not 100% ideal. The downstairs sofa-bed was quite short and narrow (140cm) and only one of us could fit in. I would therefore rather recommend the place to two couples or to a couple with children.
Apart from that everything was great. Literally just around the corner you'll find a lot of nice little cafés where you'll be able to enjoy delicious breakfasts. And the flat is easily reachable by one single bus (5C) from the airport, or even faster by metro + one bus.