I thought the extended life feature was just the pins. They are either harder steal that doesn't wear as fast, or they have a lubricant inside them and designed in such a way that they roll and even out the wear all around instead of just one side. I didn't think the sprocket was any different. They should all have the flat ends to the teeth. When they wear down to points, it's long past time to replace them.
Drawback to extended wear is the up front cost and the replacement cost. The pins are the most expensive part of the undercarriage, and the hardest to replace. You can't do it yourself, and a shop that can will cost quite a few grand to do the job, once you either get the tracks in there or haul the machine there for them to remove the tracks and do it. My tracks weigh well over a ton, so it's not a simple task of taking them off, loading them on the trailer and then putting them back on. I've done it, and each step is an all day project.
Eddie
