Very well located, about three minutes walk from Cuatro Caminos metro, but still in a side street and so very quiet. Cuatro Caminos has three metro lines, so it is ideal for getting around and is not far from the centre.
The space itself is a good size for one or two people, with a bathroom in a compartment to the side. The whole studio is comfortable, new and well equipped - it was missing a toaster, which I mentioned to the host, and one was bought for me the next day. Apart from that it has heating, a comfy bed and a sofa. Internet worked well.
All good, an ideal place and location for a week in Madrid.