In all honesty the RAM is running at such a high speed that the difference between CL(9 and CL7 is negligible at best. One is better off just getting the cheapest RAM (at the speed you want, and from a reputable manufacturer) that is available.
I don't exactly understand what you mean when you say it's running at such a high speed. For example, you can get DDR2 1066 with CL5... It's running nearly as fast, and can equal the 1333 set overclocked, with latencies half as high. I'm not making an argument for DDR2, I'm just saying you should look for lower latencies.