Great apartment for 2-4 people. We had 2 people, so had ample room to relax and move around while on our stay. It was very hot while we were there, but fans were extremely helpful so we were not uncomfortable at all. Max was extremely helpful with giving us tips of where to go, meeting us on time with a smile, and assuring us if we had any questions (we didn't need to, everything was so well explained) to message him. Great location to explore Madrid - we got public transport to and from the apartment at the start but otherwise walked everywhere in our stay. Also there is a Nespresso machine so bring capsules if you have one at home.
Only thing would be if you are over 6ft the shower is very small. I am 5'10 and I fit in the shower without bending, just. My partner is 6'3 and he did have to stoop both in the shower and in the upstairs bedroom. Not really a huge issue though :)