Back in the day when it was common to use a single servo in the wing center with bell cranks out at the aileron it was always a pain to get them to work bind free. Really rough on servos. Phil Kraft had the right idea with the original Ugly stick to run them external. I have seen throttle servos fail on gassers regardless of the linkage except the pull cable set up. Gas engines bounce around a bit and that can be transmitted to the servo especially if the servo is over driven by just a touch. If mounted on the motor box one has to worry about heat as well. Dirty, thank for the explanation, for reasons you describe I use high discharge rate batteries to overcome the resistance of the regulator and you are correct that I am less likely to have an issue with the Smart Fly regulator then a different unit. Although on my 50cc airplane I ran a single 3000 mah battery with an MPI regulator and IBEC and had no issues there either. Then again at less then 40 flights the airplane was sold so not really a good example of long term reliability. Lots of different ways to skin a cat. Sometimes when looking for every last bit of performance we have to go the route of slightly higher risk, all part of the game.