The Sonata is much more quiet than my old no-name case. It has a slow moving quiet 120mm fan that moves just as much air as a faster and lounder 80mm fan. I added the second fan, even though it mounts in a very strange place. It is on the side of the 3.5" HD rack, several inches from the front grill. I got an Antec "smart fan" for the second fan. That was probably overkill, since it is my impression that the power supply will regulate the speed of any fan down anyway, so long as the temps are OK.
The risk with this case is heat. The PS is quiet and should stay cool, but one fan can only move so much air, and the second fan does not add much to the total, given its location. I do not OC, so it is not an issue with me, but folks that do overclock, especially those that are aggressive about it, might want to look somewhere else.
I have just ordered a couple of Zalman products for my CPU and video card in hopes of making things still quieter. Little teen fans on video cards make way too much noise for their own good. Sure hope losing that fan entirely does not turn out to be a mistake.
One other thing: Antec calls this case "piano black," and I think that is pushing things a bit. It is black and sorta shiny, but the finish is nowhere near what you'll see on a black piano. I let my obsessiveness with appearances get the best of me, and put a couple of different car wax products (Meguiar's) on it to help the finish. Your mileage, and obsessiveness, may vary.
