I stayed almost a month at Abrahams place. The house is lovely - especially the rooftop terrace with the hammock - and a great place to meet other people. Rooms are clean and cozy. Abraham was not there but always responded quickly to any questions via email. He was very helpfull, friendly and took good care of me.
The neighborhood has a bad reputation, but I never felt unsafe there. I walked the streets at every day- and nighttime and was fine. The place is in easy walking distance to the historic center and about half an hour by metro from the hipper areas like Condesa or Roma.
Really enjoyed my stay and would come back.