What's best about Markus' place is the location. Its just a short walk into the old town and its very easy finding the place after taking the bus into town from the airport. The place is quite spacious, although a little bit dusty. I liked the high ceilings and some of the art work! The lack of natural light is an issue if you wish to stay in and read etc. The kitchen units need to be replaced - they are tired and old. I also had problems with the wifi router - this needs to be replaced as it keeps tripping off.
All this said, I'd still recommend staying in Markus' place (or the other flats he lists) - the location is superb, and there is plenty of old world charm about the entrance etc.