It's supposed to be quieter because of the bigger form factor allowing for larger fans.  I read in the Spondoolies-Tech thread that they measured it at 68db as opposed to the SP10 coming in at 74 (might have been 72)... at any rate, the measured difference was not very large.  Of course, with the larger fans, perhaps there won't be the high-pitched whining quality to the sound.  At any rate, if I do purchase one, it's going to have to be hosted.  I don't have the power to drive one of these at home... well, I *could* run heavy duty extension cords all over, but the little lady would have my head if I tried that one