My father and I flew DL Biz Elite and upon check in we were presented an invitation card to get into the AMEX Centurion Lounge. I agree, it is no big deal but the drinks were still free. Plasma TV, no restroom (they are right outside the door), a few computers w/ internet access (slow), somewhat comfortable chairs, etc.) It is also a very confusing lounge to find. (take a left just before duty free coming out of immigration.

I was told that you needed to be flying in Business Class to have access to this lounge regardless of status in any FF program. I guess they guard access to the lounge pretty close.

As for the AF lounge, it closes at around 4p and you can't check in for a night flight that early to get access to this lounge.

As for security, I would leave 2-3 hours to check in and clear customs, etc. Can get pretty hairy.