Delta Airlines: it's pretty obvious from traveling on Delta that they're going bankrupt. The planes seemed old and creaky. They don't feed you, even on 5-hour flights (unless you count a box containing Sunchips, peanuts, Oreos, and Cheeze Whiz as food). And their call center in India isn't even one of the nice ones where the people who call themselves "John" and "Susan" have pretty convincing American accents. Apparently they went for the discount call center, where the reps have extremely thick Indian accents and they are completely without useful information. Don't even get me started on the check-in kiosks at the airport: I got booted out of the process no less than four times when I tried to check in for my flight.
Atlanta Airport: Nice! A good place for a layover.
Raleigh-Durham Airport: Mediocre. On the positive side, they have a Popeyes.