The performance issues are engine related. It doesn't really matter how bleeding edge your PC is, if you are into detailing or big cities, you are gonna have 20-30 fps no matter what, maybe 40 if you're looking at something away from the city. The beefiest hardware can only do so much. I have a 4790k @ 4.7 GHz, 32gb of ram, Fury X, and the game runs like crap once you start getting into the meat of the game. Some people are fine with that, but if you have a 144hz monitor and are used to high FPS, it really is hard to ignore.
The devs said it themselves on the reddit ama, they gimped the game so it would run on lower end hardware. That is where they make their money. They could optimize it for high end hardware but they have no incentive to do so. It would exclude a chunk of users who have dog shit PC's that want to play the game.
C:S is what it is, it's unfortunate because it has so much potential, but were stuck with what we've got. It's fun and a great game don't get me wrong, I tell all my friends to buy it, but it could be so much better if it actually scaled properly on high end hardware and devs made real changes instead of giving us weak cosmetic DLC's.
