d
this really depends on what you are doing. you may see minimal things in gaming, maybe. the new cpu will be the bigger thing. but for ram heay things yes it will
i have had both my razer crapped out on me and the Logitech still kicking. i like the feel of the Logitech more and just not happy with the 6 months i got out of the razer. I liked the feel of the mouse and the software/customizability that it had more than razers even tho i have a Razer headset and keyboard. i personally will stick with Logitech for the mouse.
most likely you got a legit one. the amount of effort to go through laser etching is way more costly than 20$. if it is actually etched it is most likely legit.
definitely run some benchmarks. if it runs where it should then you are golden
i agree, you are paying for a overclock chipset even tho you might not overclock it now atleast later on down the road when the 8600k isnt top of the line you can get a little more performance from it.
If you crave balls to the wall buy a 1080ti for now then upgrade to the newest one when it comes out. sliis a dying platform and is being abandonded left and right, nvidia is not even pushing it that much anymore.