I tried a cheapy leather NATO a couple of years ago and it wasn't very good at all, so I've stuck to nylon since. I just got a Tanner Bates one and it's actually pretty good, albeit relatively expensive. I doubt any of them will last especially long given how thin the leather has to be, so I expect the "cost per wear" of these to rapidly become exorbitant.
I'm going to order some nylon NATOs from CWC and was thinking about tacking at least one leather onto the order too. Has anyone here already tried them and ideally, compared them to others?