Thanks exit13a for answering the question for me. Basically, we always use online check-in and no luggage for all our domestic travel, so we hardly use the e-kiosks ourselves. I did use the counters at PHL a few months ago, but didn't notice the confusion among travelers like I saw at HOU the other day.

Internationally, we've always used IAH. Dedicated Elite International desks, and dedicated security line. Never any wait in the morning hours when we depart for HKG, and no wait in the afternoon for CDG last year either. The experience is so superior to that at HOU the other day that it's worth the extra 15-minute drive, as we don't have to get to the airport that early.