Latency has nothing to do with the quality of the memory modules.
Speed and latency is the main factor in determining how fast memory modules are. E.g. in this case both memory modules have 3600Mhz. Frequency is expressed in Hertz, which means "cycles per second". In this case 3600 cycles per second. CAS latency is given in cycles. So, a CAS16 RAM will take 16 cycles to respond and the CAS17, 17 cycles. Now, DDR4 3600 CAS16 will take 16/3600 seconds which is equal to 0.004444 seconds to respond while the DDR4 3600 CAS 17 will take 17/3600 which is equal to 0.00472 seconds to respond. Simply put, the memory module 3600MHz CAS 16 will be faster than 3600MHz 17CAS. It always depends on what applications you are using. For gaming, MHz in general (or for the new AMD Ryzen processors) are better, as long as the latency is not too high. For scientific calculations, lower CAS latencies would be more suitable, so that the cycles would be shorter (faster), (also ECC memory) "ECC" (error-correcting code / error detection) would be more suitable. If you need more detailed information see this Wikipedia link
https://de.wikipedia.org/wiki...
Hope this helped.