OCA has the Xoxide Dual Voltage 6 Port Baybus in for a review today. The dual voltage settings allow you to run your fans quieter when the system doesn’t need the extra cooling, and the dual LED’s look pretty sweet. Here's a snip from the review.
"The only performance improvement you will gain in having installed a Baybus is the ability to change the voltage output on your fans. Normally the Baybus operates in full 12V output, and with this version you have the ability to turn the fan off completely, or operate it at 7V. When you operate the fans at 7V the noise is GREATLY reduced. So when your not running your rig at full tilt, you can give your ears a break and run the fans at 7V."

Review Link : OCAddiction