If you have an earlier unit (Series 3 or older) they came with a polymer (PVC?) anti-static mat that worked very well but tended to collect dust and wasn't very attractive.
After I had my Sapphire refurbished by Sota with the new Series 5 platter, the acrylic super mat was bonded to it. It is much more attractive, doesn't attract dust and has at least the same amount of resistance to resonance.
No additional mat should be required either way. If you choose to use one anyway, you will have to raise your arm to account for the change in thickness.
Hope this helps & happy listening!
