Everything was perfect, Mirek answered quickly and met me for the check in, gave me useful tips and he's been very gentle even if we didn't need to meet again, I could leave the keys inside and go away for the check out.
The position of the apartment is perfect, close to tram and metro, near the Flora shopping center and in a safe area.
The apartment is in the basement under the street level, but I didn't feel uncomfortable.
I definitely recommend it!