The final number in the timing (10 or 12) indicates the length of time that the ram is active before it goes to a precharge. Theoretically, the longer time, or larger number, is better, as it gives a longer time to read before having to be charged again. At the same time, some systems will run better with a smaller number. Either OCZ or Corsair would be good, with the edge perhaps going to Corsair. I don't know that it would be significant, though. Personally, I'd go for the OCZ, because I could use the money saved on something else which might make a bigger difference.