It's always a little strange flying an airline other than the one to which you've already pledged your allegiance. Particularly, when (a) it's "your" airline's arch-rival and (b) you intentionally chose to fly it (saving hundreds of dollars in the process). Every seemingly inconspicuous thing is unfamiliar -- the electronic check-in kiosks that ask for unusual information, the flimsy paper boarding passes, the foreign concourse layout. And you don't benefit from any of the niceties you've come to enjoy elsewhere: dedicated check-in service, fastlane security lines, priority boarding, and first class upgrades.

More than that, you're handicapped by a lack of knowledge of the system. That's probably the biggest weakness. At United, I know the system like the back of my hand... often better than the gate agents and customer service reps. (Relevant tangent: Scheduled on an ORD-DFW (to DEN) flight, I walk up to an ORD-IAH (to DEN) flight and ask if they will route me through IAH instead of DFW. "I'm sorry sir, but United doesn't fly from IAH to DEN, so we'd have no way of getting you home." ... "Excuse me? I can assure you that United has many flights from IAH to DEN." ... "Sir, I've been here for 10 years. We don't have flights from IAH to DEN." ... "Well, no. In fact, United five daily trips between those city pairs!" ... ARGH!) Now, flying American Airlines -- I've taken only a handful of flights on AA in my lifetime -- I'm lost. Bottom-of-the-barrel passenger, at the whims and flings of their system.

It's a little exciting, I guess. Probably good too to sample other products. But I want my United miles!!!