Stayed there for 10 nights. 200 meters away from "El Capricho" metro station. Half hour from downtown Madrid by metro, line 5. Plenilunio shopping center less than 2km by feet (20 min walking time). Near the airport. Very big apartments for a very reasonable price. Helpful and polite staff. Good cleaning. Food, coffee and other beverage at very reasonable prices in machines near reception desk. Shuttle service to and from airport. Very good quality wifi internet free access. Definitely would be there again.

We stayed just for one night while in transit. The rooms are actually mini apartments and are very spacious. The carpets in the rooms are dirty and need to be thrown out, they are past being cleaned. Although this is advertised as an aparthotel and there is a microwave, stovetop and fridge, there are no plates, cups or silverware so unless you plan ahead and bring your own stuff the kitchen is no use at all. Its located in a business area though and we had some good food at a restaurant near by. All in all I would not stay again.

We stayed here 3 nights at the end of trip and it was really nice to be in an apt instead of a hotel room. Clean, spacious, great layout, great airport shuttle service. The location is nice if you don't mind a residential area 1/2 hour metro ride from the heart of Madrid. We felt like locals, so it was fine for us.
More positives: nearest metro has an elevator, it was easy to get to from Alcala by bus (Canillejas then metro or walk a mile along park); great large park nearby; great price. fast and free wifi in the room.
The downsides: very noisy at night inside and outside apt; no big grocery stores nearby, few restaurants, baby crib was falling apart and hall too narrow to put crib in the bedroom.

Very safe, clean apartment with free shuttle to airport. 100 meters from metro stop. Good wifi signal. Professional staff and free ice in the lobby!!!. High value.