You are unlikely to find much better value than this in Madrid. This place is smack in the centre of the city where everything is going on. This does mean that on weekends, it can be quite noisy outside at night but you're never going to avoid that if you stay right in the center.
I found the room comfortable and ideal for my 1-week stay and the property felt secure (3 different keys / doors to get to your room from the street).
Private bathroom was good and included sachets of shampoo. I found the shower water temp could be slightly temperamental but it was ok.
For the incredible value of this place and it's location, I would stay here again and recommend it to others.