"Our tests demonstrate fairly little difference between a $225 LGA 1155 Core i5-2500K and a $1000 LGA 2011 Core i7-3960X, even when three-way graphics card configurations are involved. It turns out that memory bandwidth and PCIe throughput don't hold back the performance of existing Sandy Bridge-based machines. "

So that's not a bad CPU to pick.

-> The change in screen lighting could be some setting. One of my laptops uses an automatic brightness system. I turned it . Another laptop dims the screen a little after a bit to save power. That's a feature and not broken at all.

I fear that these new features could upset some owners as the folk that sell these are selling boxes and don't know their products.

I don't know what "explore" is. I know Windows Explorer but items that won't open is nothing new for that. Maybe it's time for Windows to be replaced as folk need something simpler?