[PVE] Staff Ele
They’re fine. Just go zerker. 30 Fire. Stay in Fire. No real point in leaving the attunement in PvE.
Viable as in can you complete every single dungeon as a Staff Ele? Yes.
However, I’ve found S/D generally more efficient (i.e. faster kill/clear speed) particularly in its ability to apply large amounts of Might stacks which Staff simply cannot do at the same level.