I have one custom, and the service for the knife I've gotten is nothing short of phenomenal. It's a custom from Walter Wells of Virginia. I was using the knife at work to cut some cardboard a few months ago and realized when I got the knife made to my specs, I never even thought about the thickness behind the edge. The grind it got was pretty chunky behind the edge and didn't slice as well as I'd like. I messaged the maker, fully expecting a high price tag and a lot of waiting for a response. Within a day Walter had agreed to take the knife back and regrind it to a high flat grind at no cost to me. Not only did he go above and beyond for the making of the knife, going so far as to do a frag pattern on the scales (which he didn't offer), he reground the blade and shipped the knife back on his one dime. Of course I tipped for this service.
That's 10/10 customer service to me!