I just replaced my cam pads after 138K miles, along with the chain.
Well... when I say "I replaced", I mean Max at RSBarn replaced them. I provided financial backing for the venture...
Here is what they looked like. I apologize for the low quality pictures, taken with my cell phone. They're probably good enough to give you an idea of the condition.
Not at the point of iminent failure, but it was definately time to replace them.
The worse of the two is the bottom pad.
We had inspected them 6 months ago and noted the grooves and pitting. This was on the to-do list and I'll sleep better at night knowing that this is done.
Just a data point.
Jamie