I recently received some interesting inquiries regarding the durability of John Lofgren's Horween CXL Engineer Boots and as a proud owner that considers his boots to be one of the top models available on today's market (and since their release in 2012), here is my reply.
Apparently, the point of contention lies with the accelerated rate at which patina on the Horween CXL develops -- I consider this to be an extremely positive and desirable characteristic.
Just the way you can't tell if unmarked vintage leather is horse, steer or cow (99.9999% chance it's cow -- don't fall for the ever-popular "horsehide" buzz word used as an attempt to bring in more money) there's no way to determine the durability of certain leather based solely on touch. You gotta wear your boots, people.
Having owned the black Horween version (along with almost all of John's boot offerings) since 2012 and putting them through the wringer for close to five years, I can say, with complete confidence, that his boots are made with the highest level of construction and leather built to withstand the heaviest wear (check out the below photo showing the boots in their post-Line Crossing ceremony condition)
Since 2014, the boots have gone through a few rounds of cleaning and conditioning, which regulated the patina, and now all they require is an occasional light buffing (as seen on the right boot in the first photo). Also, the Vibram soles show signs of wear, but won't need to be replaced for several years yet.
Bottom line is that not only do his boots looks good, feel buttery soft and have an amazing vintage profile, these boots are worth every penny and will last a lifetime and some.