I don't quite understand your question. You say that this power supply is not good, then you say the CX series was better? i'm confused. On a side not, I have the Corsair tx 750 watt, and it's amazing, but if you prefert les clutter with cables, I recommend the HX series, it's modular rather than standard
If you are looking for the naming convention of Corsair and their relative performances, then it would be:
TX and HX are almost the same in performance, but HX one's are modular. That's all. Hence the HX one's are more expensive. The AX one's super efficient one's and Gold certified.
The CX400W was the only CX series PSU that Corsair had, only recently they added some for wattage ranges to it, like the 430W, 600W and a few more. The 430W wasn't good. The 400W is quite impressive. So if you are going for a Corsair PSU, then VX should be your starting point. The new CX one's are too new to be commented on except the CX400.
The old CX400 was a higher quality unit than the new CX430.
Corsair does seem to be cheaping out a bit with the new PSUs, I haven't seen any good reviews for the CX500 but it doesn't even have an 80+ rating.
I'd go for a Seasonic 520w instead for more money: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
People are talking that this PSU is not good, that old CX series was better is this true?
its not a bad PSU but it does not live up to other corsair PSU in that range. the VX 450 & VX550 are much better PSU. unfortunately they cost more so consumers who know little about PSU other then the watts on the box where choosing coolermaster, thermaltake, ocz, etc., PSU. The new CX is suppose to compete against them, frankly I think its priced to high.