I notice that some SODIMMS have half the latency of others. For example, most "value" types are CAS latency 5 whereas some higher-end SODIMMS have CAS Latency 2.5. I know the clock speed rating of different memory chips is irrelevant since the memory/FSB clockrate cannot be changed (overclocked) on my iMac even if I wanted to (which I don't). However, it does seem like lower latency memory would have to provide better performance than higher latency. Intuitively, to me it's like the way a faster hard drive will make for a faster computer than a slower hard drive. Am I wrong? Is there any reason, other than the greater expense, to not buy lower latency memory? By the way, my imac is a 2.16GHz C2D, in case that has any bearing on things.