I had a great time at Karin's "boathouse" studio! It's not on a boat but overlooking the canal - ideally located right by the Nieuwmarkt in the very hear of Amsterdam.
Karin was a wonderfully welcoming host, very flexible to welcome me (I unfortunately arrived later than expected but she accomodated my schedule very nicely), gave me a quick tour of the appartment and even showed me around her place (she and her family live on the 1st and 2nd floor while the studio is on the groundfloor) and gave me some good tips for local shopping.
The room is very nice, a comfortable bed, a nice sofa, some closet space, a desk to work if needed and the internet works perfectly well.
There's a list of recommended places to eat which is provided by Karin, a guest book where everyone can leave heir own additional tips... and if that's not enough to quench your curiosity, there's a guidebook & map of Amsterdam to help you get around.
I really recommend the boathouse studio for your stay in Amsterdam!