I stayed in Niko's room from September 5th to September 9th to attend a cancer conference in Prague.
House: The house dates in its core from the renaissance with a baroque overhaul and has a small fountain in the stairway. It seems to have been renovated quite recently, using the techniques necessary to professionally renovate a historically significant house. For example, in the room, the wooden beams of the ceiling are visible; I am pretty sure these are original. They add beauty to the atmosphere. The house itself (the parts I saw) is in very good condition.
Room: The room was a clean, roughly 3m x 4m room. It is part of an apartment with several rooms, two spacious and clean baths, and a large shared kitchen. Check-in and -out was uncomplicated.
Location: The location is unbeatable. Hradčany: 10 minutes walk. Malostranské náměstí: 5 minutes walk. Charlesbrigde: 10 minutes walk. Monastery Strahov: 15 minutes walk. The old city: 15 minutes walk.
Restaurants: there are several with good food for a good price within 5-10 minutes walking distance. However, despite being an area with many hotels and restaurants, the place is quiet with very low traffic.
Guidance by the host: I know Prague quite well. Therefore I did not need that.
In summary, this was one of the best stays in Prague I ever had. Definitely the best price-performance ratio I have seen in a very long time. It is a real catch—five stars in all categories.