The museum is itself a houseboat, so it clearly is not very large. One can accomplish a thorough visit in 20-30 minutes. The price is quite reasonable, and you can spend more or less time, depending if you are interested in the books/albums on display in the living room. Kids are discounted based not on age but on height! One descends steep stairs down into the boat, so accessibility should be considered in planning a visit if that is a concern.
The sleeping cabinets give you a sense for how cozy (or claustrophobic, depending on your viewpoint) it can be to sleep on a houseboat. There is a running slideshow of houseboat life and clips of lots of other houseboats. There are ads for actual houseboats for sale, so you can get a sense for that, and the maintenance required to keep one. I learned, for example, that there are no open houseboat slips in Amsterdam, the only way to get one is to buy a houseboat already in one! I was also fascinated to learn about how they are heated and how to get furniture in and out via an opening in the roof. This is definitely a niche, but if it is one you like, it is a very enjoyable and not time-consuming visit. If you have more time, you can have a tea or coffee on their roof and enjoy the "garden" of potted plants there.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.