I have found the CoolerMaster LED fans to be fairly quiet. Not dead silent, but even at full speed I don't notice them over my Antec power supply, which itself is pretty quiet. The ones I got at SVC (non CoolerMaster) are a little louder, but they are all on a rheobus, and don't run full speed anyhow. Though that does dim the LEDs, but that's alright too. The SVC AngelMod deals are nice. 😉
\Dan