...current 777 is a brilliant and incredibly reliable machine - Boeing certainly got it right, but I hope the new ones are quieter inside and get up a bit higher than the current one, which is the turboprop of the jet world when operating at gross weight.
Yes, abit unfair... low cruise altitudes but only at ISA+20 temps and more as is normal in the M.E., IF the company programmed FMC margins are fair and your Optimum and Max Alts are true!
I know Cathay 777s out of the US are carrying the "excess" of their Airbuses out of that region currently :-) (here we go... I'm running for cover)
I agree with your 777X comment and am also interested in the revamped Hyundai330, which is proving a winner too.