I've got an H80i with an LGA-1156 system, and the tubing joints to the right of the pump interfered with the closest RAM slot by no more than a millimeter or two. Attaching the pump at a 90 degree angle solved it, though its a bit of a shame not to have the Corsair logo straight, especially with the nice customizable RGB LED.
I think the issue is the 1156 socket, though. I've never heard of any such issues with 1155, 1156, or 2011(-3).