Rolf's apartment is very well situated in the center of the city. It's an easy walk to the museums and Vondelpark (plus, there are great bakeries just a few minutes walk away called Noë and Holtkamp). Access to/from Amsterdam Centraal and Schipol airport is also easy (bus or subway). Lots of restaurants nearby. The place is spacious, comfortable, and as advertised.
Rolf provided me with details to self check-in and was responsive to my questions.
This is a good homebase while visiting Amsterdam. Center but not in the busiest area.