OK, this is interesting. There are 2 products listed here that I've enjoyed immensely.
Someone mentioned a pair of speakers that I just recently acquired as a "mistake". I've been really enjoying them but found them a bit "bright" when pushed.
Over and over the comment I've heard made most consistently about them was they "are very revealing of the source" and the source I listen to most is vinyl. I've been running my phono stage with no loading since I bought it and love the detail and "air" and pretty much everything about it. I decided to try adding some loading last night, and everything changed for the better. Did these "bad" speakers suddenly become "good", or was it operator error at worst or lack of properly tuning the entire system at best?
I think I need to still play around with loading settings, but my point is that some gear is more system/room dependent than others. I have a feeling some of these "mistakes" were more mis-matched components than something inherently "wrong" with the gear itself.
In most instances I buy things without having ever listened to them and haven't made too many "mistakes", but there have been a couple along the line. Even those were more listening preferences than there being something inherently "wrong" or "bad" about whatever it was. One person's "bright and edgy" is another person's "highly resolving and detailed". Another person's "warm and engaging" is someone else's "boring and subdued".