My group of 5 stayed here for 2 nights. It was comfortable, elegant, clean, and spacious. The location was pretty good, but sadly we were there while the train line near the apartment was under construction. It is probably much easier to get around when you can take the train (we rode the train elsewhere in the city and it was great).
Christian was a very accommodating host. He lives in an upper unit in the same building, so it was very easy to check in. He also took a good amount of time to show us around the apartment and then mark places on the map for us and give directions.
Two things to note though, the listing said a dryer and 2 bathrooms were included, but the dryer was entirely absent (though Christian happily supplied us with a drying rack) and the bathroom situation is 3 rooms, one with a toilet, one with a bathtub and a sink, and then the last with a shower and two sinks.
We really liked the apartment and enjoyed our stay in it.