If you are reading this to help you decide about this room, I will make it easier for you: TAKE IT! you won't regret.
David and Lenka are such a nice hosts, David gave me lots of tips of what to do, eat, where to find the best views of the city. We got to follow must of his tips and they were really good. He also offered us transportation to get to the bus station, it was more than excellent. About the room, the same! It is big enough, clean. You have your own bathroom and small "kitchen" (quotes are because you have a fridge, microwave and sink) which was perfect, you also have coffee machine and a welcome beer! (which we didn't drink since we arrived really late and tired every night :/ ). The location perfect, the neighborhood calm and safe. I stayed with my parents but I will recommend it to any kind of trip. Thanks again for letting me stayed we had the best time in Prague :)