Transcend is good brand. I've used Transcend's DDR2 & DDR3 RAM on six builds over past 5 years. They are all working flawlessly. (CAS) latency, or CL, is the delay time between the moment a memory controller requests RAM module to access a particular memory column & the moment the data is available at the RAM output. In general, the lower the CAS latency, the better. CL9 is the normal latency of 1333MHz DDR3 RAM. But from my personal experience, I know it is possible to run them at CL7 (7-7-7-14 which is faster & tighter) @ 1333MHz without increasing RAM voltage.