Originally Posted by
Yarhead
Really, my gut feeling on what you should do depends partially on when you will begin (and potentially end) your travel schedule and how many elite qualifying miles and on which airlines you've already banked this year.
That said:
Based on what you're looking for, AA seems to be best (mainly and only after achieving Executive Platinum), and DL is not far behind, even though DL gets a bad rap for its difficulty with online award booking. UA would be more of a contender if it had upgrade potential, due to its ease of award booking (but remember that mileage accumulation is weaker). I know you mentioned that upgrade potential isn't as much of a priority right now but could be in the future... if there's at all a chance it will become a priority, then I'd recommend going with DL/AA if your regular, long distance flying is relevant long-term.
I could take my actual advice in several different directions, but it'll all depend on exactly when your new flying schedule begins and ends, and what happens after that. Please let me know.
+1 Lots of great info here by Yarhead and other FT members, but the bottom line is that I think Yar hits the nail on the head with this recommendation. Flying back and forth so regularly, the OP might well come to care a lot about upgrades, in which case AA clearly has it over UA. And you also might care about redeeming your accumulated miles, in which case AA clearly has it over DL.
Yet another factor is that UA has become horrible at dealing with the inevitable problems that stem from weather or mechanical difficulties. Putting aside the temporary labor issues with its pilots, AA is much better at handling those irregular operations. I can't say how AA compares with DL in that regard.