P-E-R-F-E-C-T!
I've been in this apartment for 2 weeks.
Great location. Malasaña is an amazing place to be with great restaurant, bars, cafes, and superb ambience. For those who are looking for the touristic center - 5 minutes walk and you are there. Really no need to stay right in the center - it is not as authentic as staying in Malasaña.
The apartment itself is beautiful, great for 1 person or a couple, and it is equipped with everything that you need, really. Manuel thought of everything. The bed is super comfortable, the internet is very good without any problems, you have a washer, good shower, 2 TVs, a coffee machine (with capsules) and more. And on top of everything, it is very quiet. Good location + quiet, you can't ask for more.
As for the host - Manuel is by far the best host that I ever had. Helps with whatever he can, more than he needs. I had a lot of suitcases, and he helped me to carry them into the apartment, and when I had to leave he came specially to help me with the parking and carrying the suitcases down to the car. Also, there were few freezing nights in Madrid and Manuel went at night to buy a radiator in addition to the AC, even when I insisted that it can wait for the morning.
So what else can I say - best Airbnb experience. Go for it.