TT mats DO INDEED make a difference.. I have used felt, Audioquest Sorbothane mat, the paper and cork Ringmat, they all do different things. The Ringmat was best for me.
Proper set up is paramount.. I have always had a professional do it for me but it can be done by yourself. changing tone-arm wire or the cable from your TT to your phono preamp can also effect changes. Changing the power cord to your preamp and power amp can make a change in the direction you want also. I have had great success with Cardas Golden Power cord, very warm, 3-D and inviting.