Your memory performance WILL benchmark faster, but memory speed is not really a bottleneck in modern systems. (most important is that you have enough, once that is accomplished, memory speed is a secondary, mostly insignificant issue) That is why when you put faster memory in a PC, you really don't see any difference. You have spent money or you are putting effort into a NON-BOTTLENECK part of the system.
If you want to do some big overclocking, the 1600mhz memory will give the overhead room without danger of exceeding your memory specs. That is what faster memory is good for.