Regarding the noise on these things... I'm half tempted to take the switch apart, move the innards to a 2U chassis (hack it up), and do some fan and PSU swapping to make it quieter.
The PSUs on these things output 12v only, all other voltage regulation is onboard. I'll have to spend some time to figure out the "sense" pins and the fan wiring but that can't be too difficult.
Another reason I'm considering this is because I have a number of other systems in my rack that are very low power. They don't draw more than 40-60w each (at full tilt), so doing a "top of the rack" 12v power supply and then distributing it to the switch and these systems, should be more efficient, in theory (vs each PSU doing it's own conversion).
I'm in the middle of building a few servers that I need, but once that's complete, I have a strong suspicion I'm gonna tackle this...