dustcover up, down or off

if you don't hear a difference, do what you want...if you do hear a difference, the answer is the same

Exactly.

but I recently read an opinion

And it was exactly that , an opinion. Nothing more.

What works for one may not work for another person....somethings just have to be tried first before an opinion can be made.

I agree with what the others have said so far, with one caveat: If there is even a remote possibility that the dust cover could fall down while playing a record, I would either play with it down or removed entirely, as the effect of the dustcover slamming down could easily cause damage to your record and/or the stylus.

My two cents worth.

Any turntable I had always was better with the lid off.The lid resonates easily and transfers the vibration to the platter,or record.Different models had different vibration characteristics,but worse with the lid on,up or down.

You should listen and act accordingly but if you are not sure, I think it is better to leave it down. It can help guard against and reduce rumble/feedback from airborn sound waves eminating from speakers when that occurs. I do not know of a downside in terms of sound quality leaving the cover down on most all tables I've worked with.

FWIW, I keep mine down mostly though I do not hear an audible difference. Sometimes, for convenience, I take it off all together (yeah baby!) because my hinges are just not as taut as they used to be and the cover does not always stay up anymore on its own.

Never heard the difference in all my years.

CDs sound much better anyway.