I spent 4 nights with my partner in December 2015 and I strongly recommend this place to stay in Praha. The price is great, the location is almost perfect (a 20mn walk to reach THE bridge but there are so many things to see on the way that it is not a problem at all), the flat was exactly as described, very clean and very well heated.
And the best part is that Kristina and his husband are extremely nice, welcoming and make everything they can to make you feel comfy.

Thank you again!