As countless others have said, there's quite a difference between a PC that is specced to match a PS4, and a devkit.
For example, while waiting to play NFS Rivals with a PS4 controller, the game crashed to a Windows 7 desktop with Origin and a command-line window running a script.
On the other hand, while waiting for the round to start in Battlefield 4, I pressed the PS button and got the PS4 OS menu, so unlike NFSR, it was a PS4 devkit.
One small correction, you don't need a devkit to play unfinished games; you can run them on a debug unit, which is what journalist do to preview upcoming games.