I know Directron.com themselves use weight to determine how good a power supply is. They figure heavier components makes it better. It makes sense, but I'm not sure how much! Heh. In any case, if you want to go by that, go on directron and look up and see how much their supplies weigh.
The only experience I have with a CompUSA brand accessory is as follows:
Walked into store. Inquired as to whether store carries any D-LINK NICs. Was told normally yes, but none currently. Said machine ran out of spec, he asked overclocked? Said yes. Asked if any other were comparable and if he could recommend any. Saw Netgear, SMC, and Linksys lying around. He says he recommends D-Link, but any should be all right. He said just don't get the CompUSA brand cards.
Heh! Don't know if that follows with their other things, but that's the info I have.