I've been pretty lucky with my watches. I don't service anything until the it stops keeping time or the crown feels weird. I've never serviced any watch, including my 1998 Speedy and 1996 Cossie a12023.
I rotate watches once a week and always measure it Monday morning and then again Friday afternoon. I've never had a watch hit plus or minus 10 seconds per day. I let my watches rest when I'm not wearing them. No winders.
I also have a 2006 Explorer II and a 2009 Reverso Grande Date. I'm a little more worried about the Reverso since it's a more delicate/intricate watch, so I don't wear that one quite as often as the others, but I'm gonna keep rolling the dice. No services until the watch says so.
Edit: I had my Grandpa's 1970 Accutron serviced when I inherited it a couple years back since it wasn't working at the time. Bob at
http://mybob.net/accutronrepair.htm told me that it was in great shape and would have probably worked if I had replaced the battery. Due to the age and sentimental value, it was important enough for me to get it serviced, though.