I think this 837 figure is the official rate but I don't understand what real-world significance it can have when pesos are actually being bought and sold at something north of 1100 to the dollar.
The only benefit an exchange rate policy has is that it makes a countries' exports competitive on the international market. This is relevant for developing countries intending to build up a trade surplus. A floating exchange rate is better for developed countries with balanced trade. The previous exchange rate policy in Argentina didn't really serve any purpose other than to paper over domestic problems. There was no "grand strategy" behind it, so it needs to go.