I bought this gaming PC instead of building my own — and it's the best decision I've ever made

One very important feature you left out was the power supply. What was in the build? Many OEMs skimp on the PS to buffer profits. 30+ years of building & repairing PCs, this is not something to casually overlook. A weak supply can leave you with random reboots, Component failure, and data loss. Even if they start out fine, a couple of power surge/brown outs later, they could plague you with problems.