The flat corresponds to the description: it is in fact the third floor of a house in Brooklyn. The floor itself does not have a door, but the various rooms in it do.
The equipment is a bit old but functional. There is no kitchen but a microwave and a fridge, as said in the description. There is still some cutleries etc. to make yourself some breakfast, for instance.
Alex is kind. He was flexible with us with respect to our arrival and departure times which was highly appreciated.