On price
ex-CAI DONE6 US$9160, AONE6 US$14117 so not that close, but all depends on your view of the importance of F.
On that routing - only 5 F segments (I think) is CAI-LHR-JNB,BKK-SYD,LAX-LHR-CAI
Tokyo-SYD. No F on NRT/HND-BKK. I would consider going via SIN instead so you can get F on the QF A380
In the US many choices - New York, Miami, Boston, San Fran...