This is a great question. To further the discussion, I purchased a VPI peripheral ring and center weight recently. After a few weeks I noticed (for some odd reason) that the peripheral ring would wobble up and down very slightly. This was unnerving, but it actually changed in its degree of wobble with each record. I can only come to the conclusion that these records (many of which were 180 g and 200 g vinyl) are not only warped, but have varying degrees of thickness, especially around the perimeter.
Flat Records?
Perhaps this one has been kicked-around already, but can someone help me understand why records cannot be consistently manufactured physically flat and with a decent quiet surface? Maybe I am buying the wrong records. I just tried a copy of Aqualung on the 200 gram Quiex SV-P and it was no where close to flat; not even remotely close. About one out of every five or so seem to be non-flat, as in completely warped...