Antonios place is great! Value and price relation is good, comparing that you are renting a place in Madrid :D. What we liked about the place that there is a working dishwasher, the apartament also was very close to a cute bar called Amore (a great place to sit with your friends).
However there were a few problems in the apartament. There are a few places on the floor where you can get your socks torn and ruined because there are some metal pieces sticking out, so you should be careful while walking there. The next thing is THE NOISE. The apartaments windows are right above a small but very noisy street and during the day the noise is fine because it is a big city with a lot of people. But during the night you can hear people shouting and also the garbage truck comes at 3am to pick up the trash. It was quite annoying and sometimes it was hard to sleep but we dealt with it.
Also, the water temperature was very confusing. We were 5 people staying there, and for all of us to get warm water in the shower was imposible. Only about 2/3 people would get warm water in this apartament and the other last 2 people would get to shower under icy and cold water. Which could be refreshing if you like showering in cold water :D
Other than that the stay at Antonios Apartament was good! :D