I agree. I have almost always had great experiences with the AA RTW desk. The phone is answered promptly, the agents are generally knowledgeable (or readily seek help when they need it), they are pleasant, and carry through on the bookings efficiently without undue delays. This service, even more than the lower surcharges with AA, are why I have our RTW tickets issued (or reissued if originally issued by another carrier) by AA.
I would also like to add that I have had very favourable experiences with AA agents at airports when doing a reissue. Most of my experience on these reissues has been with the AA agents at YVR; they are great even when they have to do a lot beyond the normal. For example, today I had RTW tickets re-issued with AA at YVR and the original e-tickets (booked with only 10 segments but expanded to 18 additional ones after 2 segments were flown) not only had to be paper tickets but had to be hand-written! The AA agents (at least 4 of them were involved at various stages) spent several hours preparing the ticket and checking it over. Not only did they not resent this extra work, but they were cheerful throughout and were very diligent in assuring that all the many pieces (e.g., stapling fare construction printouts onto every coupon) were done correctly. I hope my positive experiences with AA agents on RTW reissues are mirrored elsewhere.