There's no material difference. Pick based on the JL equipment operating the long haul flight. Which JL route has a better hard product?
<Redacted> Spring weather is the same in both places and your AA schedule will change 5 times between now and then, anyway. Assume that whatever you book, the AA connecting flight will change both times and equipment.
The only caveat I would add is that on the eastbound, I would much rather reenter the USA and clear customs at DFW. I>D connections at ORD are very inconvenient with the remote Terminal 5. But since you specifically asked about the westbound flights, D>I is fine at either airport.
Last edited by JDiver; Jul 19, 2019 at 1:23 pm
Reason: Redacted meta reflecting on other members