I been using the hitec 81mg with good luck, so have others at my track..
I had asked a few pages pack about servo mouting in the CRC cars weather to go in the mount or the chassis down low. Well i tried both and i sure like it best down on the chassis. On carpet it just seems more predictable. It also feels more securely mounted. The 81MG only has 2 mounting hole tabs so shoo-gooing the the chassis was much more secure then only 2 screws in the crc mount. If im not mistaken the steering is not nearly as twitchy.