It's not that people hate the CX, it's reviews are OK when you measure a new unit. However when you read a tear down it is clear that it is made to a budget from cheap parts and is more prone to fail because of that.
Like I said, it isn't garbage like some of the no brand units you will find but personally I wouldn't put one in a gaming PC. A quick check and the price difference between buying a CX and a far better supply in the UK is about £15-20 so I really don't see the point unless you're working on a desperately tight budget.
I think more than people hating on the CX there is a club of people who leap to its defence probably because they bought one and take it personally when they read criticism, it's a budget PSU intended for that market. If you're buying enthusiast hardware why cheap out on your PSU?
Rather than retype information about the CX I will post a couple of reviews, basically generally the performance is 'OK' but the cheap quality of components mean you could well not be getting the W rating printed on the side. There are build quality issues in general with the unit that make it a lottery and its cheap fan is more likely to start making a noise and crap out.
Most of the positive reviews I have seen of the CX series are by people who have never taken the lid off the thing, they just measure its ripple, 12v etc and these are pretty acceptable compared to a more expensive unit.
http://www.overclock.net/t/1431436/why-you-should-not-buy-a-corsair-cx430-500-600
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=416