The unit is extremely quiet-it seems that most low-power units are these days, and even the higher-power units are getting there. The Xtreme 630W does have a blue LED in the bottom side fan. I find blue LEDs to be cool sometimes, but extremely annoying if they cannot be switched off, and this one cannot be switched off.
Rosewill's Xtreme line of power supplies is an extremely decent contender in the market, with a variety of wattages ranging from paltry 630W up to the extreme 1000W. However, nothing sets them apart, other than the extremely low price: it can be had for under $80 at fine on-line retail outlets.
I would like to see a power switch for the blue LED-those can get extremely annoying at night.
ThinkComputers gives the Rosewill Xtreme 630W Power Supply a 9 out of 10 score.