I feel rude asking for a 'favorite' agent, so it's kinda hit-and-miss.

In any case it seems like they defer to the rate desk as final authority for questions like this, suggesting that AA trains them to go that route and doesn't duplicate the training on them directly. So, much of what they sound expert about comes from remembering what the rate desk said the last time someone asked. For common, non-controversial issues all the regulars seem to know what they're doing.

Cathay NA res appears to pretty similar, but again you'd have to challenge them to see how much the average CS agent knows. The Cathay we talk to in Colombo is the Fares Group, and seem like they have more rate-desk type knowledge. I did send that email and will post the answer.