Jharr
Thank you. Mexico City has a bad reputation and to a certain extent that reputation is well earned. However, if you are careful and don't indulge in "high risk behaviour" there is no reason why anything unpleasant should happen.
You do have to be wary of the local constabulary though. In over 15 years of visiting Mexico the only bad experience I have ever had was with the police, I managed to extricate myself and my then fiancee out of trouble by doing a runner fairly sharpish so nothing bad happened but I've heard enough tales from the locals to give the cops a very wide berth.
Even with the violence and corruption, Mexico is a wonderful country with a rich and vibrant culture, the food is amazing and the locals an absolute hoot. I love going there.