Some Corsair PSUs are made by Seasonic (HX 520, 620, 650, most of the AX series are the ones I know that are), not all are (such as HX 750, 850, 1000, TX series). Do you have some evidence that the new CX series is made by Seasonic? And even if they are that doesn't necessarily mean that the new CX series is as high quality as most people expect from Corsair.
cumulusjames, personally I would suggest the Antec Earthwatts Green EA-380D, aslong as you have a power cord to use with it. As, unlike the CX series, the Antec Earthwatts Green 380 has actually had a high quality review done on it, which showed it in a positive light, at Anandtech.com. Unfortunately you won't get it from OCUK. Unfortunately it isn't any cheaper. Anything cheaper you will be taking a chance with and are unlikely to be getting a unit that is very quiet or will last very long, so really you're better off getting it right first time.