Autoride Shocks

I have a 2001 Tahoe with the Autoride system. I was wondering what kind of life everyone was getting out of the shocks. My Dad just bought a new Tahoe with the Autoride, and it seems to ride a ton better. I know mine with 80,000 miles on won't ride as good as a new one (plus I put real truck tires on mine). I was just curious as to the life expectancy of these shocks.