The 'Centro 2 dorm Garaje, wifi free' we rented in Madrid was outstanding. We were looking for a quiet, relatively central place, with a garage and free wifi, and this one ticked all the boxes. The apartment is near the Toledo Gate so is only a 10 minute walk to Plaza Mayor. It is in a quiet neighborhood with a supermarket and a few restaurants nearby.
The apartment itself was spotlessly clean and appeared to have been recently refurbished. It has lovely furnishings, is spacious, and is well equipped with all the electrical appliances you have at home. Daniel and Elena were very helpful with travel advice and very gracious when we arrived an hour late, courtesy of Ryanair! The apartment has all the coking utensils you need and the extras that make it feel welcoming like tea and coffee, oil and vinegar, and salt, pepper and spices in the kitchen, washing liquid in the laundry, and bath gel in the shower.
We were only two people, but the apartment could easily take four as there is a trundle bed in the smaller bedroom, and a second toilet in the laundry. It would ideally suit a couple or young family, as the large cupboard is in the main bedroom.
I would rate this highly and recommend it as comfortable, pleasant, good value and an excellent base from which to explore Madrid and the surrounding area.