VA or UA >>>>>>>>>>>>> AC (wouldnt even consider that because of the connection and general suckage of AC business)

For experience, VA clear winner, this isnt even close vs United - in every aspect (except LAX connection), for convenience, I guess its UA

Why wouldnt you get any miles on VA? - its a Delta partner.

What about NZ - much better business than UA and AC, and still Star Alliance. Just make sure AKL-SYD is on a widebody