I have both. Different pro's and con's.
The leather one would, in most instances, be my number one choice, IF the snap were tighter (this problem has been noted a long time ago in equipped.org's evaluation and both of my leather pouches have it, don't know if it's already fixed): it sits higher, the belt loop is narrower (in the cordura model it's huge), and it really looks good. On the minus side, due to its "open" design (lots of Wave visible), it tends to allow the tool to gather quite a lot of lint (under the hem of my sweater or jacket).
The cordura pouch is higher (or more "closed"), sits lower, stays shut securely (though the velcro pad is quite small), and would be my number one choice, e.g., in the woods, if I'd have a *very* wide belt on.
Hope this helps.
Markku
PS. There are aftermarket ("universal") cordura-pouches, which allow the Wave (or some other tool) to be put *horizontally* on a belt. Sometimes I prefer that.