Despite any small differences, these are both very good power supplies.
One of the things I really like about the Corsair i models is the information you can get from them. You know that already because you have an i. I am not really sure if "more recent" makes any difference, in that the HX1200 is still a very viable option even though it is a bit older. I think on paper the Asus is the better power supply, but I wonder if the 1000W is enough. I know, I know, it's enough today, but if current trends keep going, then it may not be enough for very long. Just because we don't have a 600W graphics card today doesn't mean there won't be on in a years time, and they say to get a power supply that is about twice that of your graphics card. Personally if you are going to spend that much money, I would buy at least 1200W to ensure it is good for it's ten year guarantee! Oh and one more tiny advantage of the Corsair is you don't have to change your cables, they are the same as the HX850i ( not sure about the ATX cable but at least that only requires one cable to be swapped out ).
