I own a Raven one and met Thomas Woschnik, asking him about using a copper mat. He advised against doing so, bcs he said that in order to work correctly, the copper would have to be fixed to the rest of the table, as it does with the Raven AC. Having said that, my previous TT, a Scheu Premier came without a mat, and then-owner Thomas Scheu advised me against using one. When I added the Living Voice Mystic Mat, however, it was of the best upgrades I ever made. So you have to try for yourself, I think, probably the TTW is worth a try if they offer a trial policy.
Regards,
Florian Hassel