We loved our stay at Hugo's apartment!
The location is ideal: it's short walk to the museums, park, and other tourist spots, it's in a wonderful neighborhood filled with shops and restaurants, yet removed from the street so it's quiet and private. The apartment is just as cool as it looks in the pictures. Note there is no elevator, but you get used to it. Lastly, Hugo was a wonderful host. He met us upon arrival, and was available throughout our stay for questions. He stocked the fridge some drinks, fruit, and candy which was a lovely touch.
I would highly recommend this apartment for a stay in Madrid!