The Rosita is a lovely little place to stay. The location is ideal: very close to the Central train station and walkable to the whole city.
It was winter and I was afraid the boat might be cold with the freezing temperatures outside, but with 4 radiators inside it was quite warm and toasty. The mattress and comfortable and the cabin is exactly as pictured. We stayed 9 days and cooked breakfast in almost daily.
Friedrich was a gracious host and quite helpful, charming and witty.
I would definitely recommend the Rosita to anyone looking for a little something different than the usual hotel rooms.