Just wanted to share my experience on a recent pair of AM operated flights SFO-MEX and MEX-SFO. Flights were AM operated and our tickets were on AM stock with AM flight numbers. Me and my travel companion are both Skymiles Silver Elite.

While making our reservation I wasn't able to select a seat other than in the last few rows of coach even though my Skymiles number was entered. I tried online chat and was told that I'd have to pay for seat selection. Tried again a few weeks later and was given seats in AM+ but the whole process took almost an hour online and lots of back and forth discussion. Agent seemed very hesitant to give me the seats for free.

Checked in at home and noticed that my Skymiles number wasn't on my boarding pass. Logged into am.com and verified that my number was on the record. At the airport I asked to be placed on the upgrade list since I didn't see my name on the screen. Agent looked at my boarding pass and said "OK. I just added you". I pointed out that she didn't touch her keyboard and asked how she added me? She just said "If you'e not Platinum there's no point". Flight went out with 2 empty seats up front.

On the way back, checked in in Mexico City and asked to be put on upgrade list. Had to be added manually. Agent acted like it was a chore. Didn't clear. Flight went out with a full FC.

Checked dl.com a week later and my companions points/miles had posted 5 days earlier but mine didn't post. Requested missing miles from DL and included boarding passes and ticket number. DL replied that they needed a copy of the ticket even thoughh it was an eTicket and I'd already provided the ticket number in the missing miles request.

All in all, not very smooth.