As SLF
777 : Noisy as hell, but with fewer seats in J the meal service is quick. The seats suck though as its impossible to sleep unless you are laying on your back. ICE is pretty much the same. Y on the 777 can be described as hell on a long haul over night flight.
380 : The beds are narrower but Full Flat beats everything. Its a pleasure to sleep on. Despite the fact that you are sitting in a tupperware box ( yes acres of plastic boxes ) with your feet in a hole in front of you. Meal service can test anyones patience, sometimes it is possible to take a nap between courses. Its quite, extremely quite when compared to the 777. But god help you if you are at the very back and someone decides to have a party in the bar. ( yep a certain flyertalk member is famous for the booze fest in the back )
To sum it up if it was not for the seats, would prefer the 777 over the 380 despite the noisy cabin. All I wanna do is eat as fast as possible if needed and sleep, hard to achieve that on a full A380.