I have the umnumzaan which I procured first. Next is the large 21. Between the two, initially I prefer the Umnumzaan over the 21. However over time, I edc more the 21. Indeed, the umnumzaan do have a distinctive wear mark. The more it is used the wear grows too. I still remember when it was new, the ball lock sits like <30% onto the lock face. The lock bar in operation now sits very close to its opposite presentation slab however its not touching and is holding its position.
Do note that there is no issues with lock stick or rocking or the sort and it is as smooth as it was as new. On the other hand, the 21 have minimal wear on its lock face and no visible scarring except the shinny section where lock bar meets the lock face.
In my opinion, how both folders are deployed does affect the locks. On the umnumzaan, its mostly by flicking and on the 21 its more of a relaxed sweeping motion in my case. Nonetheless, I love both of them as they have not given me any issues since I own them way back in 2014 compared to other makes.
