I'm DCA also and like US for these additional reasons:
The US credit card is churnable for 40K miles each time, no fee, and gives priority boarding, a 5K discount on US metal rewards, and a 10K annual bonus. Plus Barclays only pulls Transunion.
The US international routes out of PHL are really nice and PHL is convenient.
The US off-peak to Rio twice a year for 30K rt if you have the credit card is outstanding.
I hate Atlanta.