Read these threads as they occasionally come up and too often almost casually discuss "hey, how many miles before you change lifters?". Can you imagine the howl if any other large automobile manufacturer produced an engine in which a significant internal engine component ought to be replaced at something close to annual mileage for regular automobile driving.
Friend of mine's bike was in my garage just a few weeks with a front lifter failing. Just starting to skate and just starting to make a little noise. Fortunately caught it very early. But could have started coming apart literally any distance ahead. Had less than 20,000 miles (I think that's right) since had been replaced prophylactically a couple years ago. Using good parts too. This time went with the Johnson 2313SE parts and keeping fingers crossed.
How far can a manufacturer hide its head in the sand when it can be said "hey, my Vega timing belt can SAFELY go three times as long as I trust my modern Harley's lifters."