We spent three days in Madrid discovering the city, and really had a wonderful stay. Nacho's appartement is really nice and comfy and gets everything you'll need for a daily nice life. It is also very central in the city. We never took any bus or metro and went everywhere we wanted just walking, it was pretty much enjoyable.
The area is really nice in day (quiet but with some bars and shops), and also in the night with a real life you can enjoy when you're outside but you won't hear when you're inside.
Ignacio himself is a very nice host, always available and kind, and very welcoming. We strongly recommend to stay at his place !