We stayed in Martijn's house with our 3 small daughters (2, 4 and 6) in August this year.
The house is a very typical Amsterdam house, located very conveniently near the center but in a quiet area. Tramways stop a few minutes walk from the house, and there's also a big supermarket nearby, as well as pharmacy's and several cafes/restaurants. Even with the small kids and the stroller (no bikes!) we managed to get around very easily and efficiently. As an indication, we took the girls to Nemo, Artis, Vondelpark, Scheepsvaart museum, Erasmus Park, canals tour and Zaanse Schans - we all enjoyed very much. Still about the location, there's a major train station a few tram stops away (Sloterdijk).
The house is spacious with a very nice garden (with trampoline and slides!) which was great for the kids and we enjoyed very much the kitchen/dining area and the view to the garden.
Martijn was very nice and friendly and let us use Netflix!
As a typical Amsterdam house, it is built on two floors, the one below being partially 'underground' - this was a bit strange for us at first but we all got used to it.
A nice addition to the house is Doutze the cat who definitely considered us as guests in his house :) he is very sweet and was a big attraction for my girls.
Martijn and his wife have been very kind to us, always available for questions even during their own holiday and it was very nice to meet them.
This was our first try at air b&b and it was very positive, also from the point of view of experiencing what it would be like to live in Amsterdam as a family.