Staff or D/D for PvE?
For pve I like dagger dagger because it’s the most fluid imo. I use it when I’m playing casually. However for dungeons in use staff, and fractals dagger focus. Offhand dagger supplies damage for the most part but staff gives even more damage and utility. Dagger focus gives you more team utility that can be valuable in certain parry make ups
I have mostly played with the staff. Recently, I changed to D/D, primarily just for something different. Using staff all the time was getting kind of stale. But it seems to work just fine, so I think either would do. Just choose what looks like fun.
It all depends on what ur doing, for general pve (farming around maps) D/D is the best.
For World Bosses Staff is the best choise since u got access to range, utility and aoe.
For leveling up, D/D is what everyone goes for but u can use whatever u feel like… in fact u should try everything for a while so u get to understand how it works since it always comes in handy at some point.
And last, For Dungeons/Fractals u can use a 4 diferent weapon sets:
Staff: its the best choise in a party that already has Might being caped at 25 since it gives u the most damage.
Dagger/Focus: its mostly used when u know u will have trouble surviving since u get Swirling Winds and Obsidian Flesh along with several blast finishers and longest fire field.
Scepter/Dagger (Lightning Hammer): its a fast burst setup with little personal utility except for ur field blasting… this one is not used very much anymore since warriors keep a better might uptime and ur better off with a Staff.
Scepter/Focus (Lightning Hammer): basicly same as the above one but with more utility and better survivability damage diference between the both is not that great, but then again these weapons are mostly used when ur party lacks might.
this is the optimal setup for pve, but u can ofc use whatever u want having fun is the goal at the end of the day :P
bottom line… Staff always ends up winning when u dont need anything but to deal damage, while other weapons fill the gaps that staff doesnt.