I also wouldn't have a backpack with any valuables on your back.

Be extra vigilant on public transit, and be careful you don't get too intoxicated at odd hours and make sure you keep your eyes on your beverages.

Generally, streetsmarts that get you through Europe will get you through Argentina.

Also, if you see packs of youth in a group, especially at night, just 'hanging out' cross the street.

I err on the side of taking taxis more at night than I used to.

You should be fine.