I stayed in Meli's place for one month. It was excellent value for the price. The location is perfect, right in the center of Madrid, next to Puerta del Sol and Plaza Mayor, the main square in Madrid. Walking distance to all the cool neighborhoods and multiple metro stations.
The apartment itself faces away from the street, so it's extremely quiet and peaceful at night. The hallways look sketchy, but don't let that deter you. I hardly ever saw anyone during the entire month, and the elevator was a life-saver with suitcase and groceries. The studio itself is beautifully designed with a nice view.
When I arrived, I noticed that the space was very clean and organized. I appreciated the well-equipped kitchen and cleaning supplies. Washer was hugely beneficial, and the microwave was a plus. The AC was a LIFESAVER during the July heatwave. Wifi worked well for the most part, with only a couples times having to restart the router.
Only real issue I had was with the toilet/plumbing. After a couple weeks, the shower started to have trouble draining properly. And the older toilet system stopped flushing properly, so it got backed up/wouldn't drain... ensuing a very disgusting situation. Meli was gracious and responsive, coming over as soon as I brought it up. She's very sweet and communicative. She said she'd bring someone over to work on it, but I'm not sure she was able to find a technician because no one ended up coming. I bought a plunger and had to sort it out on multiple occasions myself. Nothing against Meli, she was very responsive. Just hopefully something that won't afflict future visitors, because it was very unpleasant.
Thanks Meli for a beautiful stay in a beautiful city!