As others have said, the biggest problem with Karina's boathouse is that once you arrive, you will never want to leave -- and there is so much to see in Amsterdam.
Everything about the place makes it clear that this Airbnb is no spare-room afterthought. Karina has added charming (Netherlands-centric) touches throughout the boathouse that offer a constant reminder that you are somewhere special. A tremendous amount of thought and love has gone into the space.
Alice and I chose to have a couple of simple dinners and long breakfasts at the boathouse, so we could enjoy looking out at the canal and watching the water fowl.
It's a quick trip to Central Amsterdam, the Museumplein etc. The Buiksloterweg ferry from Amsterdam North, to Central Station is part of the fun. Very quick and a great chance join Amsterdamers in their daily routines. Karina was a terrific and accessible host. During our stay there was a minor and unavoidable utilities hiccup. Karina was on it instantly and all was well before it had any effect on your trip or our enjoyment of Amsterdam.
We are already scheming to figure out how to stay in the boathouse again.