I would also suggest going bonesaw over bp. If your enemies are smart and see u are building wp vox they will get armor and the armor shred will be far more effective at dealing damage than the crit strikes would. I would not get both because that is just overkill with unnecessary Fire rate and you'd be better off with a bonesaw and just a straight dmg item like another sorrow or tyrants. My build is very similar and I will be posting it soon.

In my experience I have foudn BP to be VERY useful. You can crit for insane damage and 3 hit people. I do prefer bonesaw as my final item though and I may even get it as my 4-5th

Good build, but I would recommend not getting a breaking point on Vox. It doesn't help out as much because your are a ranged hero and it doesn't give enough wp for ranged heroes. Instead of braking point I would advise getting a bone saw. Instead of that serpents mask, since life steal won't help you enough late game, get a tyrants monocle. Overall, great build. But you need to add more detail into the stages of the game.