I had Bose noise cancelling headphones and was seated up the front of the B777, so the noise didn't bother me. But if I was near the engines, that GE90 noise would drive me mad:https://www.youtube.com/watch?v=vamypKla9i4
That's a high quality recording. And yes, that droning start up is particularly bad. If your international flights are only 6 hours you wouldn't care, but if you have 13 hours in one of those things, then it is bad. The A380 is for sure much quieter, but I didn't like the seats on the Emirates A380.