Not sure what V Australia have managed to do to the 777 - but sounds the same as what they have done to every other aircraft they run!!
I fly around 40 legs a year on EK 777's - usually in economy, and I have always found their aircraft very comfortable, and never noisy.
I was forced to fly on a Virgin brand flight (Pacific Blue) a week ago - my first for over 4 years when I vowed to never fly them again. That flight simply confirmed my throughts of 4 or so years ago. NEVER again - 1hr 45 mins late departing as staff could not reboot the computer and eventually after an hour of sitting on the hot tarmac with the door open they decided to complete the papaerwork manually. Once airborne food choices were non-existent and it took over an hour to complete the food service on a 738 with less than 50% load. As for their slippery, uncomfortable leather seats - they can keep them!
So.....can't shed any light on why your V Asutralia 777 was noisy and uncomfortable -but it seems to be a Virgin trademark!!