I cannot verify that this is still true, but I remember when AA had a first bag in 8 minutes, last bag in 20 minutes standard. Do not know if that varied based on airport size or not. Whatever the standard is, they can't be meeting it routinely of late. Miami is particularly challenging. I try not to check bags, but when I do, I plan on 40 minutes when arriving DCA on mainline AA. I usually stop by the club, order a drink, hit the bathroom, then go to baggage claim.

I do not know what Delta does differently on the ground, but they almost always deliver within 20 minutes. When I lived in Atlanta, bags were almost always on the belt when I got there. This past Sunday, I arrived DCA on Delta. I got the message on the app that my bags were enroute to the claim while I was in the restroom after just walking off the plane. Sure enough, I walked to the baggage claim and all the bags had been delivered. Granted, I was on a CRJ-900, and not mainline.