I stayed in the flat over a period of 2 weeks and I must say that I had an AMAZING time! Ricardo is a great host, and super friendly guy. He puts himself out of his way to make the stay more enjoyable, whether it was bringing me to see some salsa dancing, enjoying a beer, or presenting me to his friends.
The apartment in itself is super well situated, right in the heart of la latina, and the beating heart of madrid. It is a super lively neighbourhood, with many bars, and restaurants as well as markets...etc.
The room was ideal for my needs, quite simple but comfortable.
over all I can't think of anything necessarily bad about my stay, I had a great time, and I highly recommend it. in just a few words: affordable/friendly/well-situated/buena-onda!