When we booked this apartment we didn’t know how central it was. Literally a 20 minute walk to anywhere in the city. The Prada and Retiro are very close. La Latina is 15 minutes away. Plaza Mayor maybe more than 20 minutes, but not much.
I think Plaza Santa Anna - which is right up the street- is the nicest plaza we saw. There are many high end boutiques in the area if you want to shop.
The apartment itself has everything you need. We made breakfast every morning and even cooked a meal there.
There are too many good restaurants in the area to even mention. Tip - ignore Yelp and Trip advisor and find your own place to eat. There is a restaurant every 50 feet in Madrid. Try them!