I can warmly recommend Kirsten's loft. The location a block from Vondelpark is wonderful because you can easily walk to places like the Rijksmuseum and because the No. 1 tram stops nearby, making it easy to get to Leidseplein, ARTIS, the Tropenmuseum, and more. The apartment is spacious and comfortable, and the bathroom is beautiful. Even though it was rainyJanuary, I enjoyed sitting on the tiny balcony, with a lovely view of the Vondelkerk, to eat lunch and drink a beer. Throughout my stay, Kirsten communicated frequently and clearly; she wanted me to have a wonderful experience at the place.
Two important things to know: (1) You must climb a typical Amsterdam staircase--steep and narrow--to get to the loft. If you don't like lots of steps and have heavy luggage, this might not be the best place for you. (2) The kitchen is adequate for simple meals, but it's not really set up for people who like to cook. For example, it lacks a large pot for boiling pasta and a colander.