WILL THERE BE A NOTICEABLE DIFFERENCE IN PERFORMANCE BETWEEN G SKILL 1333MHZ CL9 AND G SKILL 1600MHZ CL9 MEMORY. I ORDERED THE 1333MHZ BY MISTAKE. JUST WONDERING IF IT IS WORTH THE TROUBLE TO SEND IT BACK AND GET THE 1600MHZ VERSION.
Question was "...is it worth sending back...1333 v 1600" and the answer is IF you are going to OC the CPU 20%+ and/or game then YES - otherwise NO. 1600 will add another 2-5+ FPS and an OC system performs better with 1600 MHz RAM.
It is that simple. Personally, even my non-gaming PCs are used for large computations that sometimes last 2-4+ hours and 1600 MHz RAM cuts-off 15-20 minutes, and my Gaming PCs 2-5+ FPS is a large increase.
However, if you're just doing email, documents, light gaming then clearly don't spend the money.
OC 1333 RAM can certainly help but keep in mind there are risks of errors/BSOD/loss data, etc.