I don't disagree with BigShot here... but I do disagree with the vehemence with which he defends his point of view. I've done lots of "engineering work" - designing and testing various equipment and components - which often requires that things be measured. In almost every case, there is a reasonably well established level of accuracy that is required for a successful result. In some circuits, you need resistors matched to within 1%; in others a 10% part will be perfectly adequate. However, when I measure resistors, I still use a meter that is certified to be accurate within 1/10 of 1%. (The difference in price for the more accurate meter is inconsequential.) The reason I do this essentially boils down to: "It never hurts to be more accurate than you need to be". In engineering, we often discuss a more specific benefit, commonly known as "safety margin". ("If you start out with something that's a lot better than what you need, then it will still be OK, even if it drifts a little bit, or if you were a little optimistic.") And, not surprisingly, I tend to apply a similar standard or guideline to the audio equipment I own. Whenever possible, I don't buy equipment that is "just good enough that its flaws are inaudible to me"... I prefer to have equipment that is "a lot better than the bare minimum that I need"... (So, if I was quite certain that THD was only audible above 0.5%, I would still prefer to have an amplifier with a THD of 0.05% instead of 0.5%, "because it has a better safety margin".) And, yes, I do also agree that there is "taking things too far"...... That's why I haven't spent $10k on a meter that's accurate to 0.001%..... (However, if someone were to offer me one for only 20% more than my current meter cost, I might consider it...) And why I'm willing to settle for audio equipment that's "probably only 10x better than what I really need"..... But I absolutely don't agree that "there is absolutely no reason to pursue better performance past what's demonstrably audible" - I'll take my 10x safety margin; even if it costs a little extra; as long as it isn't too much extra.