Does the stock Kydex sheath work? Sure does. It works great, in fact. Do you need a leather version? Probably not, but it is super nice and feels luxury. This thing is going to look even better after a year of wear and patina.
The only gripe I have is the pocket clip retention is a bit lacking. It is not loose, just when the leather sheath is breaking in, I found that I would have to take the sheath fully out of my pocket to then remove the knife. After a couple of weeks of use, I am able to retrieve the knife without removing the sheath. It still slips up a bit, but stays in the pocket. Not a deal breaker, but the retention on the stock Kydex sheath clip was so much more, maybe too much. But, that is what I am comparing it to. The reason for the less retention on the clip is probably due to the nature of the leather being smooth rather than the Kydex texture. Not a design flaw, just leather is more slippery. I'd say 4.5 stars, so I am not going to ding it down to 4 because it is AWESOME.