If time really is of no importance then flying DXB-HKG-(presumably)-JFK-IAD will get the CX experience and for sure the F experience is wonderful. Maybe it's my memory as it's been four years since I flew BA F and I managed CX F a couple of times this year on very long flights... but I would not rate CX F so much better that I would go 5000 miles out of my way and add an extra hop likely on some crappy RJ to take it over BA F. I really quite like BA F, though I am a Brit so maybe the ability to get a proper cup of tea and a Full English sway it for me And while the CX bed is certainly very comfortable, well if you're gonna be asleep may as well just come back the easy way

Actually if I was going DXB-IAD I'd try to do United. Their new F looks pretty good and it's one way direct!!!!