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
Overall performance was as expected, Unreal Engine 4 is a pretty well rounded thing to utilise, so visuals are on par with the performance they require. I only ever came across a single bug, which was down to me exploring an area I was supposed to have made it to. I managed to skip half the map and end up in an area I could only traverse had certain conditions been met. Long story short, I ended up in a room with both exits locked and died of a lack of oxygen, forced to restart my entire game after an hour and a half of gameplay. Essentially the game punished me for exploring too early, which is slightly annoying. I'm also a bit miffed about the fact that there's no Crossfire driver - Unreal Engine is a big engine, and for neither AMD nor THREE ONE ZERO to make that available seemed a real loss. This is the kind of game that's going to be played on VR with some beasty systems - not supporting multi-GPU setups is a real oversight. Aside from those nuances, the rest the game was spot on as performance goes. I must say though, you owe it to yourself to play this at 60 FPS. Anything less is going to take away from the slick experience.
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.