I had a lot of rumbling/noisy HD problems with early versions of the previous model, eventually giving up and settling for my MacBook Pro (with cinema display) that has been extremely quiet and dependable. I do a lot of audio editing sitting very close to the equipment and often focus on extremely low-level sounds, so I'm very sensitive to noise from the computer. I'm keen to get the new iMac so long it doesn't resurrect that old frustration all over again. Have early buyers been pleased with noise levels and, also, does the fusion drive configuration have any noticeable affect in that sense? Thanks.