Memory Cast Latency

I'm confused on how this thing works. Isn't it the lower the value the faster the memory is? Is my assumption right or wrong? I've been looking at the beast's cast latency and I kinda got confused on how to compare this with other available memory on the market.

http://en.wikipedia.org/wiki/CAS_latency

Yes, lower CAS latency on the same clock speed is faster. How to compare it with different clock speeds? You could try doing the calculations, but higher clock speeds (over 1600MHz) means you'll have to OC. I don't know how others think about this, but I got myself some 1600MHz CL7 RAM.

Yeah. I'm getting confused on how to compare the speed of a 2400mhz Memory with CL11 vs 1600mhz CL7 Memory. 

Maybe this will help?