SLI is dying. The 960 and 1060 cards dont even have SLI capability. I will not be surprised if the next xx70 cards dont have support for it either. Really, at this point all its good for is making record breaking synthetic benchmark runs. We also know that no one should be SLI'ing 970's.... lol especially with PUBg which is sure to use more than 3.5gb VRAM.
It wont shoot any faster than you can click so... no actual advantage just the ease of use that comes with buying gaming mice. I cant really imagine a scenario where that would really even help, might be nice with a pistol but otherwise the same can be accomplished holding down the left click with an automatic gun.... you know, playing normally. Other than that I cant see it being useful beyond pistol ease of use. controlling non stop firing like that is hell for accuracy.