We rented a nice apartment from an expat from Michigan who married a Argentinian. In an email he practically begged us to bring $100 bills, which he would exchange for pesos at a much better rate then was available from local banks, which he thankfully did. When I asked him what was the deal, he told me the currency is so volatile there, the only protection was the USD, especially the $100 bill.
Most of the locals were friendly, the food was great. Public transportation was dirty and hot. We were constantly being approached by people wanting to give us "tours" around city for a fee. (We read about this before going!) The infrastructure everywhere was pretty bad, you had to be very careful where you stepped on any sidewalk. Not sure if we would go back, but we did enjoy most of our time there.