I find it challenging whichever cabin you're in, and what ever tactic I find it doesn't work ! Last year I arrived at SYD and made it to the city by 7am. Hotel allowed (thankfully) a very early check in where I had 3 hours sleep with alarm set, then made it through the day. I think a bulk of my sleep happens annoyingly on the LHR-SYD leg. Enjoy the F