I travel there several times a year for both work and leisure, and I treat it no differently than I treat Chicago, New York, London, etc. The main areas are perfectly safe during the day, at night use normal street smarts. I have heard of executive bodyguard services, but I have never seen a need for this. I think it is a perfectly safe city.

The only thing that is a bit different (although NYC has a somewhat similar setup) is that if you plan on taking taxis, there are two different types. There are Sitio taxis, which park at designated stands. These cost more, but use a fixed price to your destination. My local friends tell me they are safer.

The other type (often, though not always, painted green) are cheaper, and you hail them on the street. They are possibly less safe, though I use them extensively, as well.

If arriving at the airport, use the prepaid taxi windows at the exit. You tell them where you are going, they sell you a ticket, and you give your driver the ticket. No cash changes hands in the cab.

Other than that, be city smart, and you will likely be fine.