Regarding the EZE Centurion Lounge, I had lunch with one of my high-roller clients today and he mentioned that his AA2000 Concierge (he is a regular user of the service, gets it comped - long story) got him invited in last time he was flying out of EZE.
This is a guy that can afford just about anything but he currently doesn't carry Amex Plastic... this being related to a long standing "strife" with Amex over a mess up many years ago when his card got cut-off during a business trip in Cairo.... (another long story).
So then, regarding this lounge, he told me he was so impressed with the facilities & the services, not in absolute terms, but rather as being so far beyond anything that is even remotely offered in EZE that he is probably going to get himself a Black Amex just to be able to use it regularly. Havent been in the place myself but considering where this comment is coming from, Im thinking its worth a visit...
The combination of the AA2000 escort through Immigration & Customs with this lounge sounds like a very interesting combination.... ^