I'd say that it depends on your itinerary. I do four of these/year, and always arrange through the AA RTW desk. Without exception, I have found them great to deal with. Then, once the rezzy is just as I want it, I have the fare stored in ZAR and contact Mindpearl for ticketing only. If you start in South Africa, your options are somewhat reduced. I go there only to start the next xONEx itinerary.

That, of course, is all changing, as South Africa is no longer the least costly. IIRC, I believe that South Korea is now the place to buy (I buy AONE4s from Mindpearl, but will need only AONE3s from South Korea).

Also, if there's anything more than a token price increase, I'll probably change to the SQ-only RTW, which is around US$7,000, I think.