This year I've done Dubai/Los Angeles rtn and Dubai/Seattle rtn, I think they were on 777's, I don't really take that much notice. Thankfully though I managed to get exit row seats.

I'm 6'1, 100kg and athletic in build, sometimes the exit seats can be a bit 'narrow' when sat next to someone who is broad.

The seat you do NOT want to get is a any seat directly behind an exit aisle seat - there's a box under the exit seat, so less room for your feet.

The non exit row seats, if I put my seat back, back, and slouch down a bit (natural for me) I can then straighten my legs under the seat in front.

Personally, travelling in Economy on long distance trips is a mental thing, for myself a 7 - 8 hour trip whizzes by. I lose myself in films, TV and music and the entertainment system on Emirates is fantastic.