I was searching for a truck to tow our 5th wheel with and happened to see one for sale in a grocery store parking lot. I met with the owner, took it for a drive and then inspected it. It had 65,000 miles. The folks were the second owner and claimed the original owner only used it to tow his boat to the river and back. The current owners claimed they only used it to pull a 24ft TT on the highway. I saw the trailer and the other vehicles they had so the story was very likely. It appeared to be well maintained and service records from a local chevy dealer confirmed it.
I bought it and it now has 114,000 miles with no major failures other than a transmission rebuild. It's rated to tow 10,000 lbs and I used it to tow a 15,000lb 5th wheel so trans failure is expected.
Like others have said well maintained will last.