Outstanding service quick the quickest responses I've had so far.
The place is located in the hearth of Madrid (behind Primark Gran vía) with access to everything you'll need when visiting Madrid. Walking distance from everywhere. It's well equipped and situated on the 2nd floor with a lift.
The only thing to mention is the size of the shower as I'm not really tall (1.78m) and I wasn't able to duck and wash my legs or feet as it was really narrow.
They offer a bag drop and printer at their office only minutes away for little money which is great if you're arriving earlier or have some free time after check-out and your flight.