It notes that that RAM is intended for P67 and X79 chipsets. The motherboard I run has MemOK, so I'm certain the memory will work, but will it work to its full potential? Is it worth looking at a different set of RAM?
That RAM should work fine. The only difference was on your older P55 board the memory controller is on the motherboard and most DDR3 was 1.65v when it was new. The newer Sandy Bridge CPUs have the memory controller on the CPU and work best with lower voltage 1.5v DDR3. It will not hurt the P55 to run the lower voltage memory though.