The ranger vestment (cloth one) used to be a great choice for rangers in the beginning.
Over time, rangers were given the ability to cast barkskin, making that on use ability rather pointless, and the ac of it was dropped as well. New cloth armors were also introduced for other classes that were better overall too.
If the vestment is compared to other class specific options like the assassins garb or the penumbral vestment, it's an inferior option. They give the same ac, penumbral gives a 2 use of shadowshield which is far better than any barkskin, and bonuses to hide/ms. No arcane spell failure. The assassin one gives 2 attributes, a bunch of nice stats like bluff/hide/ms/spot, same ac.
It'd be nice if the rangers vestment no longer gave barkskin, and instead gave some skills to hide/move silently instead, maybe spot/listen also, making it a better option to take. They're hunters, after all. It'd be nice if they got some skills that'd showcase this.