I had the pleasure of staying at Johan's boat house for three nights with my husband and 13 year old son. It was a fabulous couple days. My only regret is that we didn't stay longer.
We spent a bit of time on the deck of the boat during the day and in the evening watching the boats go by in the canal, drinking wine and having delicious snacks. The beds are exceptionally comfortable. It was fairly hot when we visited. We were surprised that the boat cooled off completely in the evenings and was very comfortable for sleeping.
The house boat is centrally located and we were able to easily walk everywhere we wanted to go. I highly recommend staying here and hope to return in the future.