There is one exclusive to the choice and one shared
The Miller is an amazing tank for PvE. It's the best shield wielding tank in the game when you go to shield Miller because of the defensive Cabal Alz shield buffs and holy magic.
However it has absolutely no offensive skills except a life leaching one which is more to help you heal yourself.
Then you have a choice between Berserker, Armsman, Shield Miller, depending on what you picked. (You usually have 2 choices, just excluding specialist that only has 1 choice. There is one exclusive to the choice and one shared, usually. Note the graphic)
Berserker gets a special attack that deals more damage than some other attack skills, and a slowing one. This slow is similar to the "spin-a-web" force spell that anyone with tier2 magic can get, however, so I don't find it overly useful.
Armsman gets an AoE attack that'll only be much use in PvE. The only use I can see in it is leveling faster. Also the Armsman gets a skill that lowers the enemies’ stamina and stamina recovery.
How useful is this? Well, how useful is just hitting someone one time? Answere: not very since they can recover with a potion. (For you that don't already know, when you're out of stamina you can only walk.)
