I agree--go where your upgrade will clear on booking first.

Otherwise, I avoid DFW. There is no first class lounge and you are competing with lots of other EXPs on the waitlist for an upgrade. Plus, this is the longest of the flights to NRT.

As for LAX and ORD, the LAX flight is 11.5 hours and the ORD flight is 13. I have found myself feeling sick (time change, no sleep, too much time on the plane, ?) during the last hour and a half of some of these flights. When I flew from LAX, I avoided this time and came off of the plane feeling at least somewhat better.

ZakkW