I'll start with the good: it's a convenient 20 minute walk to the Museo del Prado, and 10 minutes to Puerta Del Sol. It's insulated from street noise, and quiet. Welcome drinks were a nice touch & appreciated.
Some candid observations: My family did not find this apartment to be cozy or welcoming. It had the feel of an inexpensive hostel with a nice looking bathroom & functional kitchen.
A set of keys didn't work, resulting in us getting locked out for a short time. One room had a broken lamp & a semi-working heater that smelled like cigarette smoke. There are warning notes posted on walls (5 euro charge for damaged towels, as an example) & the beds are uncomfortable. This place is beat up & needs attention, in my humble opinion.
As mentioned in another post, there are, in fact, prostitutes working on this street. They are "passive", and we walked by them many times with our daughters (9 & 11) without incident. We found the street & neighborhood to be active, and safe. Plenty of places to eat & drink, plus a lavanderia close by.