Thanks for chiming in, Angie -- that's helpful, or at any rate, it echoes my own thoughts precisely. Maybe I'll stick with the 2 and hope they still have the 0 if I do need to exchange. It's in stock now, which is a good sign. My Nicole Miller sheath like yours is a size 2, if that helps (and it fits snugly -- as I think it is meant to -- but well). My David Meister sheath is a slightly looser 2.
And remember a few years ago when I was considering that absolutely stunning jacket at NAS, Tahari, I think? You guessed I'd need the 0 (but this was before we'd met in person) and in fact the 2 was a better fit for me.