A really different experience and great fun. You need to be fairly agile to get on and off the boat and up and down the companion ways between the 3 main 'rooms' of the boat. The boat is in quiet harbour and the bed is really good so we slept very well.
You can walk to the excellent restaurants in the meat packing district. It is an even shorter walk to the water taxi stop and a huge shopping mall. Thomas will give you excellent advice and help you discover Copenhagen. The boat is on the south side of Copenhagen so a shorter and cheaper taxi ride to the airport.
Do try it for yourself, you won't be sorry.