I made a reservation for my colleagues who visited a fair at the RAI Amsterdam. Since they were walking at the fair the whole day, the location was not very close to the fair and even with metro it required some walking.
The Nova Houseboat, on the other hand, was a very good choice and my colleagues were sorry to not have the opportunity of enjoying it more. The house was spotless and everything was available just like presented on the website.
If you visit Amsterdam for more than one night, this is The Place to stay.