For me, being GSP based, the majority of my travels take me through one of IAD or ORD's UAX operations, and I've dealt with all of the others during the last year.

For the longest time, I considered ORD to be worse than IAD (with the exception of the indignity known as IAD-G). Maybe I'm just delusional or lucky, but ORD doesn't seem nearly as bad any more-even the T2 part. Even ORD T2 seems much more spacious, bright and less of a jampacked bus stop than IAD-A/C/D; there are a higher percentage of jetbridge gates, the gate agents are better communicators, and there are better food options than IAD-A, and it might even be better than IAD-C/D (although that is a mighty low bar to jump over).

Also going ORD's way-the fact that you don't have to deal with mobile lounges and there is a degree of predictability of arrival gates that I don't get at IAD (if you're on the 50 seaters you're into T2 guaranteed). There also seem to be fewer gate changes as well-I once walked from the end of IAD-C to D only to find that I was now departing out of A now. That's rather annoying after getting off a transcon at 5/6am.

I know-ORD UAX better than something that is not USX-PHL. Does. Not. Compute. But. True.