100% on United, thanks to E+. Seriously. Unless one is really late to book. Then you're in the lottery with about the same results in both, according to conversations with my extreme traveler AA colleagues. But E+ trumps. This could be a bit of a crapshoot for a while, though, for as long as it takes for current CO metal to get "upgraded". This may be a moot point, however, if the schedule for that is ahead of the full merger. I haven't paid attention to that.