SP-10 Mat

I have an SP-10 with a Micro-Seiki copper mat. Now that my system is dialed in in terms of room acoustic treatments and speaker placement I find the Micro-Seiki mat to be a bit too lively but outstanding in terms of dynamics and soundstage. The stock rubber mat is too dull and bloated.

Could someone suggest a mat that falls in between the two, leaning more towards the copper mat sound than stock but less forward in the midrange and treble.