The location is fantastic, the apartment is clean and absolutely lovely. It was very easy to get around through all of historic Prague on foot. We loved our stay here, and would do it again!
I would caution that guests pay attention to the bathroom situation. There is very little privacy while showering, and the curtain doesn't cover the entire tub. Also, the bathroom doesn't have a door...so you are fairly exposed.
My husband and I didn't mind, but it is something to keep in mind, depending on your travel partner :).
Also, it's 3 stories high...and you have to climb up stairs to get there. Just something to know when you book this place.