Staying on a boat is not for everyone. However, when in Amsterdam it seemed perfect and we loved our stay on "Rosita". Beware the steep steps down onto the boat (and up onto the bed!) which would make it difficult for anyone with mobility issues.
Friedrich is a really friendly and funny guy, and we found him to be a perfect host
As for the location, it could hardly be more perfect. It is very quiet and yet barely a 10 minute walk from Central Station and the Red Light District. When walking into town make sure you go via Haarlemmerstraat which is fantastic for bars, restaurants and shops, yet quiet compared to the city centre