Krystof place is quite conviniant to stay a few days. The neighborhood is quiet but community buildings means you can heard noisy neighbors from time to time...
The A metro station (which goes to Old Town squarre) is 10min walk away or there's a bus stop very close to the house which made journeys very easy.
Krystof is a helpful and friendly host. He picked me up at the airport at night and was quick to awnser me.
The cleanliness could be impproved but globally my stay at krystof's was good.