Both are high quality PSUs. The Corsair one has been made by Seasonic, while the CM one has been made by Enhance Electronics.
Anyway, The Corsair HX650 is a bit better. If you can afford the price, I highly recommend you to go for it.
It presents a great efficiency (80 Plus Bronze certified) and a very good voltage stability (voltages are close to their nominal values). Moreover, the ripple and noise levels are extremely low.
It comes with semi-modular design (it presents some cables permanently attached to the PSU).
It supports even two very high-end video cards that require two power connectors each due to the four (6+2)-pin PCIe connectors.
It provides a single +12V output that is rated for up to 52A (624W)
The built quality is excellent. All electrolytic capacitors are Japanese from Chemi-Con (in the primary there is one capacitor (580µF, 400V) which is labeled at 105º C while the cpas in the secondary are also labeled at 105ºC.
7 years warranty.
Amazing PSU...