This listing is great value for money for an individual traveler in a convenient, safe, clean, and quiet neighborhood in Madrid. It will give you an idea of how local Madrileños live.
Maria Victoria and her husband were great hosts. She responded quickly to inquiries before I arrived, and answered any messages during my stay quickly. Check-in was easy as she met me at the apartment at the appointed time. She kept in touch to provide useful tips for Madrid, especially as the Coronavirus situation worsened. Her description and photos of the apartment are accurate. To summarize, it's basically two rooms on either end of the entryway to her own apartment. The bedroom with a locking door is on one end, and the bathroom/kitchen are on the other end of the entryway. The single/twin bed was comfortable. The wifi worked well and fast enough though I didn't try streaming video. There was a small flat panel TV with a number of local Spanish channels. Several IKEA-style wardrobes were in the room, so there was plenty of storage.
The apartment was well-supplied. Maria Victoria provided a good selection of continental breakfast items to get you started. There was a microwave, hot plate, refrigerator, toaster, and utensils in the kitchen area. I particularly appreciated the availability of the clothes washer, since I had been traveling for a while before arriving at the place. Everything was very compact, but worked.
The reasons I didn't give the apartment the full, five stars are the following:
1. During my stay, the circuit breaker supplying electricity to all of the kitchen/bathroom and to the outlets in the bedroom tripped at least four times (that I know of) for no apparent reason that I could see.
2. It might have just been bad timing, but I never was able to find the water in the shower to be more than "tolerably warm." It was never really hot.
3. If it's not clear from the description/photos, the apartment is in the basement level. The bedroom has a small window, but there is not a lot of natural light if that is a concern.
That said, I would repeat that this apartment provides great value for money if the pricing remains more or less the same. The location is excellent. It is around the corner from the Menendez Pelayo Metro station. Atocha Station is a ten minute walk away, as is El Retiro Park. The neighborhood has a variety of restaurants and bars, supermarkets, and other conveniences.