I've got about 100k on my CBT Lites. I've done a fair amount of walking around...just enough to warrant sole replacement. The lining still looks great. I did "snug up" the fit with a set of gel insoles.
Overall, they still look great. I clean them thoroughly once per year and apply some leather conditioner after cleaning.
That's weird that the leather interior would get a hole from wear. Those must be some tough wool socks! (I wear Thorlo