Let's see; your build as a base, his build as an alternative:
Userbenchmark PC Build Comparison
Baseline Bench: Game 64%, Desk 62%, Work 37%
CPU:
Intel Core i5-4460
GPU:
Nvidia GTX 1060-6GB
SSD:
Samsung 840 Pro 128GB
HDD:
WD Blue 1TB (2012)
RAM:
Corsair Vengeance DDR3 1600 C10 1x8GB
Alternative Bench: Game 66%, Desk 61%, Work 55%
CPU:
AMD Ryzen 5 1600X
GPU:
AMD RX 580
HDD:
WD Blue 1TB (2012)
RAM:
Corsair Vengeance LPX DDR4 2400 C16 1x8GB
Personally, i wouldn't do that switch. Reasons:
* His GPU only has 4GB of VRAM, which is 2GB less than yours. If GPU runs out of VRAM during gaming, you will get choppy gameplay. Performance wise, RX 580 is equal to GTX 1060. Power consumption wise, GTX 1060 is 120W while RX 580 is 185W (that's 5W more than GTX 1080).
* Your PC also has SSD as an OS drive, making boot-up, game loading and shut down times considerably shorter than his PC with HDD as an OS drive. Also, you might regret giving away fast loading times and being stuck on slow HDD (i would).
* Since your PC is Asus ROG series, it has custom made fancy PC case (
amazon). Reason behind the swap could be that he wants that fancy PC case which isn't available on sale separately. CyberPowerPC builds have standard ATX cases that anyone can buy separately.
* PSU build quality and wattage. I have 0 faith when it comes to the PSUs in CyberPowerPC builds since cheaping out on PSU is way too common theme in those prebuilt systems. While PSUs in custom build PCs (Asus ROG, MSI Nightblade) can be also questionable, i have more faith in them.