I believe in servicing a auto only when its accuracy starts to suffer. I'm at over 11 years with my Serti Sub and its just as accurate now as it was when new. The watch is either on my wrist or on a Orbita Belino winder the entire 11 years. It was +3 seconds when new and is still +3 seconds in 24hours. I believe that to be "perfect working order".
pic taken last summer