sounds only slightly less than typical "shuttle loud" in stock form. but this design has a few things that may make it easier for SPCR's to tame the noise beast. most notably, it uses Apple's G5 case theory by making temperature zones: the CPU has its own air tunnel that moves are crosswise in the case, while other fans pull air front-to-back for the other parts. it still has a lot of fans, but you can probably turn a few off depending on how you're using the system. impressively, this thing fits 3 hard drives so you may need that extra cooling.
may be a good HTPC if it can be quieted. too bad shuttle didn't use larger/quiter fans right off the bat... here's a gem from the review (emphasis mine):
"really amazing noise output of only 52 dbA
....The bottom line is that the SB81P performed relatively cool and quiet
with our testbench setup. "
52db is quiet?!?!? maybe in comparison to the older shuttles. the mere thought of that many dB emitting from my PC fills me with cold fear.