Emi and his friends are great hosts, they really care about their guests. They were very communicative and offered lots of suggestions for places to go. They are friendly and helpful, and I wouldn't hesitate to stay with them again.
The apartment has been completely renovated and was very clean and stylish, and bathroom and kitchen supplies were all provided. There's an Nespresso coffee machine as well (you can buy your Nespresso cups at the supermarket). The sofa and bed were very comfortable. Wi-fi is strong and we had reception throughout the apartment. Hot water was quick and always available, even when taking 2 showers back-to-back (important during the winter!). The air conditioning unit in the living room is able to provide lots of heat as well.
Even though the apartment was on the 2nd floor with no elevator, the stairs had a low rise, so it was easy to climb the steps every day. The building is secure and located on a small and quiet dead-end street right off a bigger street. From here you can easily walk to Puerta del Sol, Plaza Mayor, the Real Palace Madrid, etc. Lots of restaurants and bars within walking distance. There is a big grocery store in the basement of El Cortes Ingles department store if you want to cook in the kitchen. It's also within walking distance to Mercado San Miguel, the food market. ATMs and taxis are easy to find in the area, and you're so close to Puerta del Sol, which is a main transport hub. So, in summary, this location was really convenient, the apartment was cozy and clean, and the hosts were hospitable and responsive. Thanks Emi!