Troll armor is more useful than before because the upgrade level requirments have been reduced. This means that isntead of level 2, you can now upgrade it to level 3 before leaving the Black Forest. That means 33 armor.
Bronze can still only be upgraded to level 3 before going to the Swamp, so the maximum you can get from it is 39 armor, but it comes with 10% movement speed penalty.
So bronze isn't really worth it unless you are playing multiplayer and can't get enough troll skin for everyone.