I tried to build a $599 PC to match the performance of the $599 Mac mini—size and efficiency be damned. I could not do it.
You cannot build a better PC at $600 using new parts. Period.
But the Mac mini is only a good deal if you leave it as is; upgrading makes it a bad deal.
I've been using a MacBook as my main computer for the past week, and I gotta say, macOS feels much better and polished compared to Windows. Never going back.