Pros of staying at Bernardo's. He was friendly, spoke excellent English, and helped out as much as he could. The Airbnb address was wrong [at this stage I think it's Airbnb's fault] and I took a taxi to North Mexico. Bernardo helped by meeting me at a station. House is in a great position. Bernardo lent me maps and Lonely Planet. Bathroom and room excellent. As I stayed there on way to Cuba and back, he gave me the key to take with me. Very kind.
Cons. The room has no window, only a ceiling opening for air and light. After over 20 hours of travel a bit of toast and cuppa on my first morning of my first day in Mexico would have been nice.