My wife and I used their mapping/custom insert service for a pair of Kenetrek EverSteps for me and a pair of Kenetrek Mountain Extreme 400s for my wife. We were not having any "problems" as we broke in the boots, nor do we have any other issues we are aware of normally. I have broken both of my ankles before, so I got the EverSteps just to be proactive/aggressive with support.
We are flatlanders who live in Florida and had never done any sort of backpacking beyond a day trip, so at the recommendation of a friend who sheep hunts every year, we contacted Lathrop and they suggested this custom foot bed, so we did it.
They sent us the mapping kits in the Spring, then after sending back the carbons and doing the consults over the phone, we sent them our boots in early Summer, and after getting them back quickly we continued to train all summer. We went on our 12 day backpack hunting trip in the NWT in Aug-Sep, and hiked who knows how many miles, with loads up to 100#, and neither one of us ever got any hot spots or blisters whatsoever. Could we have not used their service and had the same results? Perhaps....but when you are spending such money on a once in a lifetime experience, I wanted to make sure we were proactive in any way we could be, especially when it comes to our feet. If you cant walk, then it is game over.