Having done several long hauls on EK to the US they are much better than the American carriers. I'm not tall (5'7) so don't find the 777 excruciating but the 380 wins. The ICE system is one of the best in the sky so at least you can keep boredom away if you find a good TV series to get into.

I've only flown EK Y on DXB-IAH (involuntary downgrade on an epic scale) and DXB-JFK; DXB-JFK was packed to the rafters.