I have the Prothane one from
www.spohn.net
It does make the car a little rougher but my trans shifts so much better now. Are you running any other suspension mods? On my car, I am running the spohn torque arm and the ES trans mount changed my pinion angle a little bit and was causing the torque arm to hit the body on medium to large size bumps. The prothane mount doesn't change the angle and I haven't had any problems.