We arrived upon a very clean apartment in the middle of Madrid. We got very clear instructions beforehand for getting the keys (because of Covid contact was minimalised), and overall the communication with the host was very good.
The apartment was very close to a metro, but even without a metro walking to the opposite side of the centre didn't take more than 30 minutes. The neighbourhood could get somewhat noisy at night but not so much as to disrupt you in your sleep, for us it was not a problem at all. I can definitely recommend this apartment if you're looking to explore madrid!