i did 27 hours (there abouts) heathrow > LAX (2 hour sat in a room) then landed in Auckland.
Would never do it again!! Too long.
Although you don’t get jet lag going West and back when i did it, it was cheaper and you could take more baggage.
oh don’t fly with Air Newzealand, the seats are crap! Quantas are far better – TV’s in the back of the seats etc (all this could have changed it was back in 2003 😉