They are very similar, the RJ X line was brought out for the 1155 mobos and P67 chipset, while the Snipers are more of a general purpose line of sticks aimed at slightly higher performance and OCing - the RJ X also are sort of broken into three separate lines of sticks (designated by the last letter of the model numbers as to 'L', 'M' and 'H' for OC possible (Low, Medium or High) potential