As to audio quality, a conductive plastic pot will have zero effect on
audio quality.

Here's another view from Allen Wright (designs amps)
"Vishay cermet are good. One of the biggest con acts has been the
pushing of conductive plastic pots to the audio industry. I don't care
what the brand is - if they make a CP and a cermet (or even a quality
carbon) then my experience is that the cermet KILLS the CP for sonic
quality. The VISHAY cerment (made by their french wing Sfernice))
sounds. like two good fixed resistors, the identical looking CP sounds
like ****! Allen