Thanks all. I'm not really concerned about safety and don't do drugs. More looking for suggestions for some bars, and perhaps some sightseeing.
I was in DF back in 2008, and did the major sites then: Teotihuacan, Palacio de Hellas Artes, Kahlo, Zocaol, Trotsky, Chapultepex
Think I'll be staying in Zona Rosa, at the Sheraton one night and the Holiday Inn the second.
I'll also be arriving pretty early in the morning- 6am at MEX, so any good morning activities appreciated