I read a lot of reviews of the Dream before we left on our first cruise and I had my doubts about how it would be after reading cruisers' complaint. However, after riding on the Dream, I thought the complaints were very nit-picky and that the entire experience was wonderful.
A big plus was the first week in May meant there were few school-aged children on board. There were some toddlers, but the ship is so big it was always easy to find some quiet space. The pools are very small, so if there are a lot of kids this could be a problem.
The Lido deck, where the pools are, was usually crowded and very noisy with music, DJs, etc., but once you're away from the pools you really didn't hear the noise any more.
6480 is in the back, so be prepared to do a lot of walking. When walking to the front, we found that taking the corridor was fastest. There's noise from the karaoke bar below from about 9-12 each night, but other than that it was quiet. Cabin was bigger than expected, and contained enough closet and drawer space to keep it from getting cluttered.