Archer/Hunter Help Air, Thunder, Or Air/thunder Powders?

I'm a level 95 Archer using an Agility/Dexterity-based build. The last time I leveled, I gained access to a decent Gale's Force I had found some time before. It was a better rapid-fire bow (in terms of dps) than the Corrupted Witherhead's I'd used before, so I switched. I'm wondering how best to powder it, though.

Its default is only Air damage, and if I only put Air powders on it then I could put as many points as possible into Agility and get excellent Air damage. On the other hand, putting Thunder on would allow me to get extra use out of my very high Dexterity, and also improve my versatility- I'd be able to deal better with Thunder-weak or Air-resistant monsters. This is especially true in Corkus, where I do a lot of loot runs- Gale's Force can't one-shot Bomb Arrow a lot of mobs that the Corrupted Witherhead's Bow could, since there are a lot of Thunder-weak Corkus mobs.

I have T6 powders of both types. Gale's Force has three slots. What combination should I use?

 

depends on your armor. what's your full build