Having dealt with Kershaw as a retail store for 10 years or so, (1980s & early 1990s) I know they have extremely high standards, both in their product quality and in their customer service. It is not surprising to me that one cannot find the fault with a Kershaw second! Schrade was the same way, you can rarely find a problem with a Schrade that has been XXed or the stamp ground off.
I have NEVER had a problem getting a knife repaired or replaced at Kershaw, either as a Kershaw Dealer or as an individual. They often go above and beyond the call of duty and have even given me extra replacement parts at no charge. I once took in a knife that was broken for a replacement. The pattern had been discontinued long ago and no parts were available. The original knife was about $25-$30. Since they could not replace it, I was given the choice of several knives all the way up to a retail price of about $70. Needless to say I left quite satisfied with their customer service!
I will say however, I have never tried to warranty a XXed out knife. They are sold as seconds and have no warranty.
I have also not had an XXed out Kershaw break on me either.
I have a XX out Kershaw Damascus Leek which I bought at the factory sale several years ago, (it is in the next to last pic I posted above). I have carried it for years without any problems. I happened to talk to the Kershaw plant manager when I bought it, he told me the story behind it and why it was XXed out. They had a local company here in Oregon make the blades and heat treat them. When they got the blades the contractor had used the wrong steel other than what Kershaw has ordered. They worked a deal with the company to remake the blades and to prevent themselves or their contractor from having a lose the whole price of the blades, Kershaw put the blades in the inexpensive ss frame and sold them to recover cost of the blades (and frames/labor, etc.) I think back then I paid under $30.
Essentially my knife is perfect, just not the steel Kershaw had specified in their order.
I have seen some pieces in the factory sales that were damaged, XXed and sold "as is." Also some that were repaired under the warranty and replaced by Kershaw. The repaired knife is often sold at the sale, but, IIRC, they are not XXed, just marked as warranty refurbished knives and sold at a good discount.