I have tried several options on my RM10 and my previous solid state Class A amp - black diamond racing cones, ordinary brass cones (forget which brand), Stillpoints, Marigo Mystery Feet and Herbies Audio Lab tenderfeet. To my ear under the RM10, the Marigo Feet sounded the best but the cost benefit ratio may not be justifiable esp given the price of the RM10. The Tenderfeet have be consistent performers making a meaningful improvement on the RM10 and other components and also do well on a price to benefit ratio
My two cents, YMMV