I do one long haul flight a year from the Far East to the UK when I go on holiday. 14 hours with an 8 hour time change. It takes me a couple of days to get back to normal, during which I'm falling asleep in the afternoon and awake at 3.00am. I couldn't live like that routinely. Even a night turn around and back home at 8.00am or a 4 sector day is a pleasure in comparison.