And right here is the reason you found the experience acceptable:
“Intel Core 2 Quad E8500 / 3.16 GHz”
That makes it not exactly a mainstream box. The supermajority of mainstream boxes in that era were Core 2 Duos at best.
Good point. I think I’ll pull a few dual core machines out of the closet and put Windows 10 on them for testing. You can still get the Windows 10 upgrade for free by checking off that you use assistive technologies.