I stayed at Valentin's place for one month and had a fantastic stay! It's a very clean/minimalist space and I easily walked Historic Center, Roma, Condessa, etc. I found the area to be really cute - authentic Mexican spots mixed with some trendier cafes and restaurants.
Building doesn't have heat or air conditioning which I found out is normal for Mexico City - I stayed in the winter and there were more than enough blankets for cooler nights.
Highly recommended for comfort and value!