Interesting...I'll be flying LHR-LAX and back in a couple of months with BA, scheduled to go out on a 777 and back on a 747. Sounds like it will be two very contrasting flights.
Although nothing will be comparable to a NYC trip I took last year in terms of contrast, out with AF on the upper deck of an A380 and back with Delta down the back of a ridiculously awful 767. Retro doesn't begin to describe it. Basically if you ever have the opportunity to fly transatlantic on a 767 with Delta pay whatever it takes to get an alternative. Hopefully compared to that BA's 747 won't seem so bad!