The apartment was exactly as expected and it is awesome. Libor was a very accommodating host, even though we ended up arriving before the arranged time. He was still cleaning the apartment but took the time to let us in to leave our things.
He explained where we were, told is everything we needed to know about how to get into town and even had tram tickets for us, so we didn't have to worry about where to buy them.
The apartment is in a quiet residential neighborhood and is a 5 minute walk to the tram stop that takes you directly to the Prague castle. It was super easy to get to all of the notable places in Prague from here. I will stay here again when I come back to Prague.