Rodrigo's apartment is ideally located in Roma Norte. I've spent time in other neighborhoods, but Roma Norte is my favorite - great for restuarants, bars, cafes, nightlife, etc. The neighborhood is beautiful and I always felt safe.
Rodrigo was an excellent host - our flight came in very early in the morning, and he was able to meet us first thing, hours before the normal check-in time. His communication was great. When he heard I was sick he made sure I knew where the hospital was (happens to be around the corner. Luckily, I didn't need to go). He's got great books if you want to just hang out in the apartment as well. I would absolutely stay in his apt again!