G.Skill is a very highly reputable RAM manufacturer, and very seldom do I read about defective products or incompataibility issues. Still, you should also understand that each mobo has a QVL, which includes all the makes/models of RAM that was proven successful.
In regards to the the concern of 1600 vs 1333. 1600 MHz is an O.C. setting; however, if you don't specify what frequency-or other RAM settings, for that matter - to use, the mobo/BIOS will fluctuate the frequency- it will rise when the processing power is needed; decline when the workload intensity lowers. This is a power saving feature.
So the 1600 Ram should be able to work in the 1333 board, and I havent got the board yet, from what I read it sets the ram to 1333 and you go in bios and manually set it to 1600..