Great place. Very clean, and I found the location quite convenient. I was working remotely from Madrid for a week and found the wifi to be very reliable and fast.
Some reviews have mentioned noise - the apartment is close to some loud bars in Lavapiés that are open until ~4 am on the weekends so you might want to avoid this place if you are a light sleeper. I am not, and I use white noise, so it didn’t bother me at all.
I would stay here again in a heartbeat!