We spent three nights as a family, with a 5 & 9 year old. The twin bedroom was great for them and the double master room had a comfortable bed. Bathroom shower was fun although the toilet would be unfeasible for anyone on the big side.
The location is superb if you want to eat and drink well - as we did! Lovely bakeries and coffee shops in the morning and some fun tapas and restaurants for the rest of the day, and all within east walking distance.
The location is also the apartment's biggest downside: the bedrooms are both on the road side of the apartment, on the ground floor, with single glazing. It's noisy, often, throughout the night. Neighbours bringing in bins at 2am, folk leaving bars at 3am and coming down this otherwise quiet street. Two out of three nights, groups hung about outside talking loudly through to 4am. This isn't Alberto's fault, of course, and is part of the payoff for the convenience of being in the district, but double glazing would have made this less of an issue.
Finally, the apartment didn't feel clean or ready for us when we arrived. I had expected to be met by Alberto, but only discovered in the taxi over from Atocha that he was taking a last minute break away from the city. The cleaner had been, but towels and bed linen were still drying. It wasn't clear whether the beds had been changed or not - the sheets looked a little worn and used, the pillows didn't feel the freshest.
The floor and general cleanliness was so-so, as if it hadn't had a proper clean at all. My kids' feet were almost black after five minutes.
It's a shame - great location, but two big minuses that I've never had before on an AirBnB rental in over five years.