I got my Klein in 1990 with the Deore XT seatpost so that bolt lasted 17 years. It went through MTB racing in the 1990's, a Great Divide MTB tour in the late 90's, various UGA campus excursions, some giant hill jumping in Athens, a muddy 24 hours of Cannan, lots of night riding, and some MTB racing (SS and otherwise) since 2005. It even outlasted the frame which cracked back in 1996.
Today it sheared off amongst the roots of the Ft. Yargo MTB trails in Winder. It left me 4 miles from my car.
I bet today's bolts would not last 17 years. Could be my fat ass.
(see seatpost in the picture to the left)