Does it matter which airline? Is one more comfortable than the other?
Thanks

Do you collect frequent flier miles on one or the other?

Air France operates the Delta run which means -- strictly in my personal taste -- slightly better food, the possibility of free champagne at the back of the plane (or at least white wine with bubbles) and more European content from the in-flight entertainment.
What would clinch the deal for me is the AF return flight leaves in late morning, meaning two extra hours in bed.

I'm more interested in seating and schedule. Right now AF has a flt leaving CDG around 4pm and I'd like that schedule.

No, don't have significant FF miles on any. Have a few from Delta but not enough to get to Europe. Have some on my CapitalOne card about 165,000 or so.

I asked about frequent flier miles because it makes sense to concentrate your flying within one alliance. If you have some Delta miles, it makes sense to go with Air France. Seat comfort won't be much different between the two in Economy, and both have a premium economy product with more space.

AF uses their 777-300ER on this route, and they now have 3-4-3 seating, which is tight. UA's 767-300s now all have updated inflight entertainment, and the 2-3-2 configuration is more comfortable.

If I get AF tickets I would try to get seats Row 30K/L or 45-47 AB or KL. I've had those type before on other airlines and like them. I would hate it if I was stuck in a middle seat...claustrophobic!
Thanks!

In 2003 I took Delta/AF to Vienna. Went LA-NY-CDG-Vienna. When I changed from Delta to AF in NY, there was a TWO DAY delay - in the end they had to send a plane from Paris. Then in Paris we'd missed the last flight to Vienna so were put up in another hotel. Hey, these things happen.