Momo's place is in the heart of Malasaña. It's a cute little apartment, tastefully and modernly decorated with all the essentials for a Madrid stay. Within 5 mins walking, you can find coffee shops, supermarkets, restaurants, tourist attractions, etc.
To make it perfect, I would suggest Momo include a few kitchen essentials like species, salt, cooking oil, etc. We stayed for 5-6 days and wanted to cook simple meals on several occasions, but missing these essentials was a deal-breaker. Because I don't want to buy a 1kg of salt, a 1L of oil, and a bottle of pepper, to make spaghetti and an egg.
Though Momo invested in good quality windows, given the location, the streets can be lively on weekend nights. Of course, this would pretty much happen in every downtown street, but something to keep in mind if you are noise sensitive.
Momo also invested in Unifi WiFi which gave us flawless internet access.