Will definitely have to look into that Arlink. I just got my new 4G SIM card from Movistar and I'm very disappointed with how mediocre it is (although their way of sending it to me and preparing me for it was incredibly professional and surprisingly efficient). I'm particularly impatient with technology speeds (I pretty expect to touch something on my phone and for it to load before I even touch it hahaha), and I hated AT&T in the US....but this makes AT&T look incredibly reliable.
My job requires me to be going from Retiro to Microcentro to Recoleta to Palermo to Puerto Madero etc on the daily, and I get frustrated as it goes from saying "Movistar LTE" to "Movistar 3G" to just showing a few bars and having no signal (lather, rinse, repeat....all day long). So the signal is patchy all over the city at best.