From my experience:
I tried to get mine at the Post Office in Recoleta and was given a "Surely you can't be serious look" had a paper with an address given to me (convenience store somewhere, never heard of the street, ain't nobody got time for that) and she closed her window and started playing tetris or something on her shitty Nokia Windows Phone. So, I gave up with that, went to the post office on 25 May, fought with the woman because she said she didn't have change for a $100, only to find out she did after she made me go get change, then said her recharge station wasn't working, blah blah blah... Got the card at least.
Then I went to the SUBE Service Center near Congreso to register it incase I have it lost/stolen.
So, my advise for Gringos:
- Post Office on 25 May EXACT CHANGE ($15?? I think)
- SUBE Office 3 Blocks up from Congreso to Register it if you don't have a DNI BRING YOUR PASSPORT
- Patience
I'd rather pay a tiny bit extra and not be tracked.
LOL, let's break this silliness down:
1: Macri/CFK/SIDE don't care why or where what you do with the transit, and is not gonna track you.
2: SUBE/SUBTE will want to track you for actually good reasons, such as:
-trafic patterns
-train/bus schedules
-fare evasion calculation
-expected growth/decline
-network expansion
3: Did I mention that if you have to take a Commuter Train/The SUBTE/Colectivos you're not important enough to be tracked, sorry. Important people have cars/drivers take them everywhere, and even more important people have others do stuff for them. Using SUBE=Not important enough to be tracked.