Shane,
Great ears hear alike. Great minds think alike too. You are spot-on with your opinion of the Millenium mat.
I was using the Millenium mat until about 9 months ago. I removed the mat and heard the same type of observations you noted.
The mat obscures microdynamics and slows the speed and tempo.
The soundstage is much clearer and larger without the mat. One can "hear into" the recording better without the mat. The mat flattens the soundstage height/depth.
Just about everything improves with the copper top only compared to the Mellenium.
By the way, I had tried different mats and trying the copper top only about 1.5 year ago when I had my Triplanar. The triplanar was not able to detect the differences between the mats like the Phantom 2 does.
I don't use a mat any longer. Let me know if you come up with something better than the copper top only.
Andrew
