CPU: Intel i7 4790 (Stock)
GPU: R9 295x2 (Stock)
RAM: Kingston HyperX Beast 16GB 2133CL12
Motherboard: MSI Z87M-Gaming
Storage: Samsung 840 EVO (OS)
Storage: WD 1TB 7200RPM (Game)
Display: Dell P2415Q 4K
VSync ON @ 60 FPS
For the first few days pre-Early Access release, there were a number of crash issues relating to story building and DirectX on AMD. Once I'd let the dev know about them, they were immediately fixed in a daily build update. Since that update there has not been a single point of failure. I literally cannot find any systematic problems with the games inner workings. No crashes since the update, no clipping, no corruption, no weird scripting errors. This is probably one of the most stable games on Early Access available right now, which makes a rather refreshing change to the status quo of EA as a whole. Even the UI seemed to scale perfectly, which is remarkable considering games like League of Legends still have yet to fix their damn UI scaling on 4K (not that I'm bitter).
For reference, you can see how your GPU will perform in comparison to ours with this set of charts.
NOTE: Precisely 50% GPU usage means only one GPU was put under load on the 295x2. This may indicate a lack of multi-GPU support.