Personally, I find the voidstrike staff fine as it is.
It combines damage and stagger in an area, it can stagger ragers, uses no ammo.
Anything armored, switch to BB.
I don’t really see the need to touch it (besides improving blessings at some point) for now.
edit for below > Like many blessings, the 3% quell on weak spot seems like a joke for sure. Though in a horde, when I hit with a charged attack at just the right head level, it can funnyly be used to fire charged shots continuously.
Sure it’s fine. It’s my favorite weapon. It’s mainly blessings where there just aren’t any really good ones.
There is a couple decent blessings, like the one which works like barrage in V2, increasing damage of 2nd and 3rd charged shot or something along these lines.
How does that even work? Second and Third shot in a row? What about my fourth shot? Do I have to stop shooting so a new count starts?
That kind of weird thing is exactly why I don’t like the blessings we have. I want something that makes sense 
Yeah, sadly a lot of blessing’s descriptions are poor…or those blessings are actually terrible. Yay, 5% more Power on a closed ranged kill. Shocking stuff.
It might be the specific staff I have, but my Purgatus, and Trauma staff both have terrible Peril issues. Two charged up shots and I’m at 95%. Even my BB works better with a few Warp Charges to boost Peril Resistance. (I use the Feat that reduces Peril by 6% per charge) My Surge and Voidstrike are both amazing though. I can charge up the Surge staff fully 4-5 times with Peril around 85%. And it quells at ridiculous speeds. And after reading my own post I can say, yeah my other staves have bad numbers. Mystery solved! lol
I suggested in another thread to overhaul the entire leftclick of the Psyker staffs, because as of now - I never use it as either BB or right click does the job better.
They should give left click better damage and maybe make it so that by holding left click you get some zoom and simultaneously pressing right click shoots it.
Hmmmm I think I’ll have a look at the Voidstrike… I’ve been mainly using Surge and Purge trying to decide which one I prefer… Now I’ve got an even more complicated decision to make lol
This post post made me sad because ya right 
I just hope and pray we get some dev love in a balance pass very soon. 