Unless you plan on doing video editing in after effects. 16gb is to much for gaming, games will not use that much ram so its a waste of money. Spend that extra money on a video card upgrade of something.
16 GB is a overkill if you are ONLY gaming. If you are going to be rendering videos and 3D models then 16 would be good. For gamers I would recommend a 12GB. But then again having lots of RAM is good for things like multitasking with big programs(Multiple Adobe programs open at once). And no you will see a 1-2 FPS change IF ANYTHING. So should you get it? No.