The location is indeed in excellent proximity to the main sights in Old Town Prague, however it is not the most comfortable apartment. The space is spartan- provided towels were like old rags, beds are old and uncomfortable, and there is only one small cotton-stuffed pillow per bed.
The bathroom is not luxurious, and not really even clean- the glass shelves in the shower had hair on them, the white bath rug had a dirty footprint on it, and the exhaust fan was caked with dust. The shower was broken our first morning and took until the night to get fixed.
Unlike other AirBNB units, this one had no bathroom amenities (other than hand soap), there is no laundry detergent, coffee, etc., so be prepared to buy everything you will need and leave the remainder behind. As the description and other reviews indicate, there is quite a lot of noise from the street below, which stops completely by about 10pm.
Overall the accommodation was adequate.