To all above. Great point. The planes are relatively the same age as AC's 777, if not maybe even a bit older. However, the upkeep on them is amazing. Even the 35 year old 747 looked like it just rolled off the line (cleanliness/maintenance standpoint).

Good point on cabin config, as the cabin is indeed configured differently. Maybe next time i'll bring a DB meter. I did remember the first time I was on a 777 by AC, the takeoff roll was deafening. I was shocked to be on BR and to not hear that. This, by the way, was my first 777 BR flight when I noticed so I wasn't "awed" beyond belief yet. The difference in noise levels for me is like the A330 vs the 777. The 330 being very quiet, similar to BR's 777.

Anyways, just wanted to say thanks to all for your posts! One of those first world problems...