Some of my servos are pretty old and have given me years of good service. Presently I have JR 4800s and the JR 9100s in the cars I race. Also just installed a KO 2512 in my newest Mini. The KO servo is not as fast as the JR's, but I usually turn down the servo speed any way so decided to go with the slower and less expensive KO. Also it's installed in a M05M. This is a first for me cause I'm very partial to the JR servos. We'll see how it holds up to my "rough" driving.

My other cars all have JR servos, but they are much older and have been discontinued for quite awhile now. There may be better servos than the JR and KO, but I've been using them for 20 or so years and found them to be the most reliable and the best "centering" on the market.