Static electricity had been giving me fits so I ended up putting a record mat on my VPI Classic to see if it would help - it did. I listened to it with the mat on it for a while, and then went back to using the platter nude (the platter, not me - see below).
From a musical and sonic standpoint it was no contest, as the nude platter was clearly the superior musical and sonic experience.
Adding a mat added some edginess to the sound, and after removing it the music regained its naturally smooth and tuneful self. If you've been thinking about putting a mat on your VPI Classic's platter you may be disappointed. I say just go nude!