I know it's a small thing to fixate on, but the mouth-cut is a pretty significant factor to how good a cowl looks. Both Nolan versions were just wrong wrong wrong, and the Batfleck one is definitely the best of the bunch, but yeah, it could be better. The squarer kind with the "nicks" at the cheek-line just LOOKS BETTER.
The Burton/Schumaker cowls were just weird - the mouth holes were wide, but they didn't accentuate the jaw, they just made the jaw look like this thing that was barely poking out of this domed cylinder of the head/neck. And the cut of the hole under the nose didn't make the requisite v-shape.
You can DRAW Batman with an impossibly thin cowl, and an exaggeratedly square jaw with a wide-cut mouth hole that shows the whole jaw... but in real life it doesn't translate as well. That's why, on the Flash TV show, the new cowl with the smaller mouth hole actually looks better.
The cowl I posted (I actually own a cast of it) is very close to the Affleck cowl, but the minor difference in the mouth-hole just makes this minor, but significant improvement.