I visited Madrid for a day and Sergio's place was perfect. I spent all day in the city and checked into my room late that night. My flight was the next day and it was super easy to get from Sergio's place to the terminal. You can either take the Metro or hop on a bus that stops nearby and you'll be there in 15 minutes. Sergio is very friendly and hospitable and I would highly recommend staying here if you have a layover in Madrid.