Also would Impale with Stun be the best single target for champion/bosses?
Here's the thing. Double Chakrams is good when you're not pressed for time. It's great, actually. On the early parts of the game, nothing says destruction like a full load of Hatred worth of Chakrams being unloaded as fast as possible.
The reality is, once the game gets tougher and mobs get stronger, your ability to simply stand and simply spam Glaives wildly wherever you want just disappears. Glaives have a huge number of downsides that simply make them an unreliable choice in the face of better choices.
1) They can't be used in anything even remotely approaching an enclosed space. And this goes in more scenarios than people think. You can't use them from an open area at creatures held or stoppered in doorways or enclosures. You can't be in an alcove or near a wall firing at creatures in the open. And they'll also stop to hit in random thing in their way, even in areas that are relatively clearly.
2) They have no ability to be accurately used. In any situation where you're trying to hit a fast creature, or one creature in particular, your solution is the same. Spam Chakrams and kill everything. But you don't need everything dead. You need ONE thing dead. Chakrams are a waste in these scenarios.
3) They're almost entirely useless in a situation that requires you to be hugely mobile and kite.
4) They give you nothing except damage. No slows, no poisons, no damage increases or anything.
Compare it to something like Impale> Overpenetration or Elemental Arrow with almost any of the perks (Nether, Frost and Shock are all very good for obvious reasons) and there's just no real contest.
Hope that helps. I was a huge Chakram fan for most of normal, but... Sorry. It's just not very good in the face of better options. (A big problem with it, for the record, is that it gets it's best Rune very early in the game and that rune FEELS like it should have just been the default ability. Once the other base abilities get stronger runes, Dual Chakram is just easily outpaced)
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