It really depends on the job, I guess. I wore the Danner Reckonings for about 2 years straight and they were a little rough looking but still in great shape. The tip of the boot where the sole curves up the front was starting to peel. The worst I did with them was mountain climbing and some very wet environments.
Some of the dudes I worked with were sent to an area with a lot of lava rock, which absolutely shreds boots.