I have had the luck of travelling during two of the most disrupted periods this winter; out of ORD during the midwest blizzards on the 12th December, and from LHR to JFK two days ago, both on AA.

I have been very pleasantly surprised by the professionalism of AA, and how little disruption I have experienced.

On the 12th I was meant to fly ORD-JFK in A, but all four JFK flights were cancelled that day. However, when I turned up to ORD, I was already rebooked to EWR, originally in Y but on standby for P, which cleared almost instantly. After a few hours delay, we landed in EWR only 1 hour after I was due to land at JFK - and (after a few requests) I was given a taxi voucher to get the rest of the way to JFK. The whole experience was pretty painless, apart from the H/K AC in ORD being packed to the gills.

Travel from LHR-JFK (part of DUR-JNB-LHR-JFK) was also similarly painless; in fact easier. Apart from the BA agent in DUR accidentally dumping my AA seat allocation (apparently a known bug in the BA-AA software interface?), there were no huge crowds at LHR T3, the flight left on time, and I was even given a complimentary Y-> C upgrade due to Y overselling.

Overall, kudos to AA. I've had very different experiences to these in the past (as we all have), but my experience with AA has been that the staff are almost all friendly, understanding, and willing to do what it takes to be helfpul. Of course there were some exceptions, but nothing like the situation at BA - where it seems a significant number of the staff I encounter are jobsworths.