Joseph, I haven't been to Buenos Aires in almost three years. But, I wouldn't hesitate to bring any/all of my gear there. I just returned from Rio de Janeiro, which is scads more dangerous than Buenos Aires, and I shot with a 203FE, Leica M7, and Contax N1. I don't recommend this, however, to newbies. But, I've spent two months per year there for the last three years and have a bit of feel for where I can expose that kind of gear.
Buenos Aires is a much more secure environment. Unless you have a history of being a crime victim and walk the walk of a vulnerable person, I wouldn't expect you to have any problems. I would take the gear, but when you arrive, get out and around first WITHOUT it so that you can get a sense of the environment. Get a sense firsthand if there will be any risks.
I have a question, though. What will you be shooting in BsAs? I ask because if you are thinking there are a lot of 'landmark' shots to make you may be disappointed. Although it's a 'nice' city, there isn't much there that is 'spectacular.' In fact, while I was there, I looked long and hard for postcards to send to friends but could find none of any interesting scenes. But, that's me. I'm sure a better photographer could find/make interesting images.
Derek