Gear longevity (giving they were installed correct) also has a lot to do with driving styles. If a person is a proud cocky person who does not know when to let up on the gas, to proud to get a tug, and keeps hammering away on an obstacle that he have no business being on, I'd say they're failure will come sooner rather than later. Opposite a guy who seldom wheels hard trails, knows how to size up a obstacle, Keeps tire spin in check, and is humble enough to take a bypass, his gears could last a lifetime. I expect mine to last for a long time.
Mine are Yukon's made in South Korea.