Issues I see:

1) Minor, but the listing of itineraries is sorted by CO (005), then date, then UA (016), then date. So I see 3/3, 4/20, 5/7, 4/28, 5/17

2) Fare class link for a flight (to show all buckets and their counts) is not available on booked itineraries, you used to be able to click on Fare Class to show that information when looking at a booked itin (on CO this was nice so you didn't have to go to the trouble of a dummy booking to see R/ON/etc availability), but this is in-line with the old UA site (where you had to do a dummy booking).

3) I can no longer see which flights have "Upgrade Pending" for UDU/EUA/CPU outside my window. This was helpful to make sure that they would be eligible for those upgrades - this is a pretty big missing item (though I think it was expected).

4) eReceipts for 005 tickets still show "Operated by CO" on many of them


That's all I see now, time to run to catch a flight!