Last spring when my interlock driveway developed a bit of shifting, Bill and his team promptly came over and fixed it up. Before Bill left, he reminded me to let him know the condition of the driveway the year after, so that if more shifting were to develop he could come over and make a more extensive fix before the warranty period ends.
Fast forward to this spring, Paul and Bill kept the promise. The team came over, and here's the crazy part: they took out the bricks of the entire back half of my driveway, cleaned all the bricks, re-leveled the ground, and re-installed the bricks. Many hours later and after a lot of hard work, I have a brand new interlock driveway, all covered by warranty!
In Paul's words they're "only fulfilling obligations as promised", but to me this is above and beyond. Driveways are always tricky no matter what company and technology you go with, but if a company is willing to fulfill the warranty to this extent, you can be sure that they always put 100% effort to do the best job they can the very first time.