it depends
would you rather fly 15hrs non stop or fly 10 hours, connect 2 hours (as long as there's a lounge with free booze and food and shower), fly another 7?
if in y, i prefer the latter, weirdly
story of my life
go for sleep, i don't find connecting stressfull but some people do. other variables include which airlines you're dealing with. a mediocre one for 11 and good one for 3? or vice versa? or all crappy airlines?