Karl and Lisa have been very friendly ever since I decided to stay in their apartment during my trip.
The apartment itself is a little bit outside the city centre, but most of the must-go tourist spots are just one metro away. Karl & Lisa also provided some tips and a map for nearby places like supermarket which made me feel very warm.
Check-in and check-out was very easy and flexible. It definitely made it easier for me to make some last-minute adjustment to my plans.