My system description is a bit more involved:
Antec Sonata case, rear 120mm fan @ 7V. Alpha 80mm CPU cooler fan at 7V. AMD 2500 Mobile @ stock speed for low heat (45W). Internal 80mm PSU fan @ 5V (replaced with PanaFlo L1A unit). Zalman Northbridge heatsink and Zalman passive VGA cooler. Overall, the system is somewhere between 20-30 dbA @ 1m. As a comparison, my wife's Dell 5100 laptop fan that kicks on when the P4 gets smokin' is at least twice as loud and I can hear it across the room over my setup. In fact, my ceiling fan on medium (Hunter Whisper-Quiet model) is louder than my system. HD seek noise is inaudible unless you put your ear up to the case (Maxtors with max sound supression).
Then my signature applies for the remainder of the journey, except I use my high-end PPA for serious listening.
I ordered a Chaintech to compare the sound quality (and more importantly the convenience) to the Sonica. I'll replace the caps on arrival to BG 47uF/6.3V units for the output I'll use (high-res mode). I route all the computer audio through the Soyo on-board system to avoid any pops/clicks/interruptions on the audio output channels. The main sound is wired to a set of Logitech desktop speakers (with the all-important remote subwoofer, haha).
I'd like to try the EMU-1212M, but I can't really justify it at this point. Maybe in the next six months after opinions have solidified a bit more, but it's just too new to jump into yet. The Chaintech was an easy choice, $22 shipped. I mean, that's almost the cost of a full tank of gas so it wasn't a stretch.