I am on my 2nd KO2's. First one lasted about 72,000+ miles. I run 35-40psi highways and 22-25 psi when I'm off roading on washboards.
No issues so far.
As an owner of both Oregon and Montana, I much prefer Montana for dual usage GPS. Oregon's small size is perfect for my hand but screen is too small to be used as off-road navigation. I still use Mapsource to chart my routes and waypoints.