I've only done QF12 SYD to JFK twice and really really endeavor to avoid it and it's inherent transit pressures. SYD-LAX is fine, followed by a later AA flight. Generally little cost difference.
Hi- hope this is the right place to ask ? I am flying into LAX from BNE on QF then onto Phoenix on AA about 4 hours later . Do you recommend Qantas First Lounge or AA Flagship Lounge ?