Carlos was so accommodating. My international flight arrived very early in the morning, and he was fine with letting me check in early to the apartment. It's a modest place that is clean and safe, and in a great location (walkable to Museo Reina Sofia, etc.) If you can't walk to something, you're just a few blocks from the nearest Metro stop or bus line to get where you need to go.
The neighborhood doesn't feel touristy, although that scene is nearby a few blocks away if you're looking for it. Carlos gave good recommendations to some of the many charming tavernas and bars nearby, most with a local clientele.