The CX Series is made by Channel Well electronics. They aren't bad. They won't win awards for amazingness, but they get the job done and are generally reliable. I like Seasonic, and they do have some good units, but Super Flower has been giving them some mighty competition in the last few years. I have no problems owning or recommending Super Flower units.
Ah, how do you like building computers for people ? I thought about starting a side business doing it. I agree with you, but I already bought the Corsair. The deal sucked me in. It was a great price ( $38 after rebate ). All SeaSonics seem to be high quality. It's like you can't lose buying one of them. Channel Well makes the CX600M, which I read isn't bad but isn't great. LOL @ Super Flower, the name doesn't sound like they'd make quality power supplies, but like you said, I've read they make quality PSUs.
