Is Impale really worth it as a 6th link compared to other more multiplier gems? Ever since I went George Cyclooney like everybody else this league, I've always been wondering if I should take out my impale gem as the 6th link and replace it with, like, brutality or close combat. So I did some simple calculation.

Let's say my damage with 5L is X. Total impale chance on tree + dread banner is 70%, impale effect is 49%. Ignoring the ramp up and say Impale deals all of its damage at once instead of in 5 hits, with Impale gem (1.15 more damage, 40% impale chance, 59% impale effect), I would deal:

1.15 X + 0.5 * X * 1.15 * 100% * (1 + 0.49 + 0.59) = 2.346 X

With Brutality or Close Combat (59% more physical), I'd deal:

1.59 X + 0.5 * X * 1.59 * 70% * (1 + 0.49) = 2.419 X

So if you go full physical and invest in the 2 impale cluster + dread banner, impale slightly loses out to Brutality and Close combat as the 6th link, not to mention it needs to ramp up and doesn't deal all those damage up front, so if you kill a mob in a few hits, it doesn't help much. Impale as a mechanic is still a huge more damage multiplier for physical builds tho.

Note 1: if you use the impale gem, you can save 1 skill point by not having to take a 10% impale chance node. But if you use Brutality or Close combat, you have 10% increased physical damage from quality. Since it's kinda hard to calculate with increased damage, let's say they're equal.