I cannot comment about the height, but being below the LHR approach in S.E. London, and having witnessed 380s taking off over West london, I have to agree that their noise is remarkably less than other planes with 4 engines, and less than some twins. They are not pretty aircraft (though I do like the upwards curve of the wings) and I agree that BA livery does suit them very well. When a BA 747 passes over I REALLY notice the difference in volume compared to a 380!