This was built to handle 4K gaming plus home media duties.
The R7 1700 and GTX 1080 Ti together handle 4K gaming on a 60Hz monitor fantastically well.
An i7-7700K would be better if using a monitor with a higher refresh rate and a lower resolution, but that's not the use case here, and affordable high refresh rate 4K monitors (not to mention the GPUs to drive them) are a while away yet.
The rest of the system is tailored to specific needs for media playback and storage. The WD Reds are reliable mass storage. The Crucial MX300 is very economical mass storage for an SSD. And the Samsung 960 Evo is an incredibly fast system drive that's also big enough to fit several favorite games and programs onto.
I've included some benchmarks FYI.
Hope you enjoy, please comment or question below and I'll do my best to reply, or feel free to look me up on Facebook where I'm Sensible Systems.