Here are very recent experiences out of EZE --

Not counting travel time that from downtown BsAs can take 30 min on aerage, depending on mode of transportation - bus or car.

Check-in -
No status - account for 30+ minutes if there are multiple flights departing close to each other for your carrier (can't say much about UA, I fly AA)
Status - Anywhere between 10-30+ minutes. Why? Because, there are MANY people with status and only 2-3 positions open. Can get worse for 1st class when someone starts to get picky about something or other and there is only one person doing check-ins.

Security -
Here is one of the worsts experiences. It is not uncommon to see only ONE WTM open at peak times for about 200+ people. Sometimes, you find 2 WTM open. To this you have to add the following people who are allowed to cut in line -- crew, ground staff, handicapped, people pull from the line by ground staff that know they will miss the plane and let's not forget.... argentines who believe they are more important than you and need to first in line with a smile. Pluses: no need to take the laptop out of the bag, WTM set at higher tolerances. Waiting time - 10-40 minutes. More oftern towards the latter.

Passport control --
Not as bad as the WTM, but similar experiences with argentines cutting in line. Crew, handicapped and staff have their own line. Account for 15 minutes. My worst waiting time was close to 30 minutes.

Civilization awaits after you cross those two hurdles.

Cheers....,

--J