Originally Posted by NickB

Somewhat OT but bus line 8 is hardly new and will get you from Plaza de Mayo straight into the airport without having to walk any distance. Granted it is not the fastest and will take a good couple of hours from central BsAs though the odd dodgy neighbourhood or two en route and you are unlikely to find many foreign tourists in it as they are bound to be in a taxi or Tienda León shuttle, but it is available.