This apartment has been my home for a month in Madrid. It is as you see it in the photos - tiny, but comfortable and with (literally) everything that you need. For my long stay, it was perfect and it allowed me to travel quickly around Madrid (you can take the metro, or you can walk to most places), as well as being comfortable for working from home.
The bed area is cleverly separated from the main room, which makes it a bit tidier - also, I am easily amused, but I have loved climbing up the stairs to go to sleep, and I found the bed very comfy.
I think this place is perfect for one or two, but might be too tight for four.
The only downside might be the stairs to get to the apartment, but then as you climb up you feel better about all the tapas you've eaten!
Lavapies is very multicultural and lively and, as a girl, I have never felt unsafe there.
Finally, Guillermo answered all my questions promptly and kindly, and the check-in and check-out was very easy.
I would recommend this stay!