It allows more versatility if you Apocalypse all the main hand weapons for each class as it allows for more versatility in game play as the skills change. As Apocalypse only occupies one affix slot, the build variations are endless depending on which items you wear, affixes, sets ,talents and natures you add. On that topic I suggest new players , like myself, either browse other guides or just experiment. But do pay attention to block, dodge, damage, crushing blow, multi strike, proc, chance to bleed , all skill, all talent, all set affixes.
So that's the end of my guide. Sorry its brief. In summary, Furies are great in PVP and PVE. Watching players guided attacks being taken by your summons while you sneak up on them is a pure joy