Here is the thing: the games on a PS4 will look better than on your PC, even if your specs are better on paper. Why?
Because on the PS4 you can fully utilize the graphic cards power without worrying about backwards compatibility or performance for small machines. You can go all in. On the PC this is not possible.
Want proof? Ask yourself why most XBox360 games look better than many of today's PC games although the XBox is now 6 years old. The reason becomes obvious.
Another thing you should not forget is that the hardware of the PS4 won't change much in the next few years so devlopers can fully commit to its features in the their pipeline, something which is not possible on the PC. Besides the development cycle of 2 years fits much better to a stable platform than on a moving one like the PC.
In other words the still-stand of PS4 hardware specs for the next 5+ years becomes an advantage, not a disadvantage.
Here is the funny quote on the link above: "The games looked amazing, but we’re skeptical that everything was gameplay. A lot of the videos seemed like target videos, examples of what the developers have in mind, rather than actual working games"