yo, while the antec psu is indeed high quality, in my experience it is far from quiet! i really think they need to change the name because it's very misleading. i had this unit and wound up exchanging it for an enermax with a thermally controlled fan. the enermax has the advantage of having a 92mm fan as the intake so it can run a little slower. you can also now buy enermax with the "FC" function, which stands for fan control. it has a little knob on the back that you can use to control the speed of the exhaust fan. the intake (92mm) fan is still thermally controlled.
currently i'm building a new system and got the thermaltake silent purepower psu to go with my new thermaltake xaser iii case. this psu gives you control of the speed of both the exhaust AND intake fans. it comes with two controllers, one which can be mounted in a 5 1/4" drive bay, the other can be mounted in a pci bracket. i am VERY pleased with this unit - when cranking the speed way down (1500rpm) it's dead silent, if you're worried about cooling you can really crank it up and get some serious air flow going. best of all it's got a thermal protection override that will kick up the fan speeds even when you have them set low, if the unit gets too hot. all in all a really sweet unit if you're looking for quiet and control.
good luck,
joe