The apartment is in the fifth floor without elevator so I would reconsider if you are traveling with big luggage. It is not so close to the center, it’s 30min walking. The green line of the subway is really close but I did never learned how to use it, unless you know Czech, it is not a big advantage.
The room is OK but I didn’t love sharing the bathroom so I wouldn’t chose it for a second time.
The host is helpful when you are there but before arrival, the communication with him was not very easy, although he was very comprehensive when I told him my fight had an important delay and i got to the apartment later than arranged. He was also very helpful and printed my flight ticket for me, thank you very much.