I stayed 3 nights in Jans apartment and it was great. It is very centrally located but yet very quiet and I slept very good (also due to the supersoft comfortable mattress :) ).
Jan is a super friendly and relaxed guy and perfect host. As his kitchen was under construction during my visit, he gave me breakfast vouchers of a nice cafe close by. He can tell a lot about the city and even took me on a tour on his motorbike through the city and it's surroundings! Thanks a lot!
I would definitely recommend Jan's apartment.