I spent the weekend here in Sander's lovely house with four friends, and I can truly recommend it. All communication with Sander has been excellent, he answeared every question quickly and really made us feel welcome. The fridge was filled with both essentials and not-so-essentials (but indeed appreciated), the house was clean and tidy, and the beds nice and comfortable. As five grown-up ladies we were a little bit concerned about noise from Leidseplein, but in spite of how near the house is to the entertainment spots, it is still nice and quiet.
The location is excellent, with everything you need or wish for within walking distance. The house itself is lovely - you get what you see on the photos, and then some. We were lucky and had lovely weather, so we could enjoy morning coffee on the roof terrace.
I would stay again any time - this is my fifth visit to Amsterdam, and by far the best.