Sissi's apartment is beautiful and cozy and has everything you need (and a little bit more) in a small apartment. For us it took about 20 minutes on foot to get to the city centre, which is great. The neighbourhood is also very nice, do try the burger and the beer at the Beaver which is on the next corner!
Sissi's replies were always very quick and helpful, she even let us leave our luggage in the apartment before check-in. Getting to the apartment and accessing it were very simple.
I very much recommend this place!