What hardware purchase taught you the biggest lesson about specs vs. real-world use?
I don’t necessarily mean a product that was objectively bad. I’m more interested in hardware that looked fine on paper, reviewed well, or seemed like a reasonable upgrade, but turned out to be wrong for your actual use case.
Examples could be a GPU that aged poorly because of VRAM limits, a case with good thermals but awful build ergonomics, a motherboard with annoying firmware quirks, a cooler that measured well but was unpleasant acoustically... such things.
What did the spec sheet or review coverage not prepare you for, and what would you look for differently now?