GOL is fine, much better service than say Aerolineas or Flybondi, but if you don't speak Portuguese or Portugñol you may have a difficult time with them in Brazil (the majority of their staff on the ground really do not speak English or Spanish). The airline is firmly geared towards the Brazilian traveler.
Also the online booking experience for non-Brazilian cardholders without a CPF can be difficult, make sure you select the Argentine flag at the top of the page if you are paying with an Argentine card or the US flag if paying with a US card - otherwise you're going to waste a lot of time.