Brilliant flat about 250m from Puerto de Sol, 500m Plaza Mayor with loads of great eating places right on your doorstep. (Bar across the street makes particularly good coffee.) The area is lively but the flat is high enough that any noise is minimal. No problem getting a good nights sleep!
The small roof terrace was an unexpected bonus and made breakfast time particularly pleasant in the sun. Nice surprise to have OJ, milk and coffee supplied but lots of small shops nearby if you need to top up supplies. Large fridge, microwave, cooker and coffee maker if you really, really feel like cooking. And a washing machine too (which I suspect most people are way to busy enjoying themselves to use).
Air con in bedroom and living area was efficient and quite but we found it wasn't really needed even at 28C - see the roof terrace comments.
Liliana, our host, arrived right on time with all the paperwork explained how everything worked and made the whole check-in process, for a first timer, straightforward - 10/10.
In short you can have every confidence that if you book this flat you will enjoy your stay - 5 stars all the way.