The location of the apartment is excellent! It's on a little street right off the main road, and within easy walking distance of many of the must-see sights and tons of restaurants/cafes/shopping. Otherwise, there're two metro stops nearby and flagging a cab can't get easier. The apartment's also very clean, cute and comfortable, with everything we needed and more. Would definitely stay in this apartment again should I have the chance.
In addition, Leonardo was very welcoming, and is a great host. He provided a lot of useful recommendations and tips, and was super easy to reach and communicate with. He also went beyond helpfulness, taking the time to call Lost and Found when I left my jacket in a taxi since I barely spoke any Spanish. Thanks, Leonardo!