Hi Cliff,
Many products to choose from.
I used the Marigo signature mat for awhile. Had a definite impact sonically. Mids and highs appear to be more liquid and mid bass / bass seems to be a bit more present. However, it does impact the apparent "speed" of the transients, "air / space" around individual instruments, and imaging specificity. Definitely a try before you buy. Can purchase from Music Direct with a return policy. Be advised it will not work with some CDP's that have minimal vertical clearance between the drawer and top of the "slot" on the front of the machine.
If your system is a bit "top" heavy and lacking overall body, dimensionality and warmth, you may like it.
Hope that helps.
Gordon