QUOTE(decondelite @ Oct 24 2018, 14:06)

OFC does decrease the clear time of DwD. Only with rounds of 3 SGs. It empties the equivalent of more than 1 full SG HP bar (usually around 1.5 for me) with a single click, therefore it's good.
On the other hand, I do have tied Vital Strike, and I don't think that stopping the hovering 2 seconds to chip off 1/2 a SG HP bar at best, which I'd have depleated with normal hovering in the meanwhile, can be considered as remotely useful. That is, I'm not even putting in the equation the fact that the SG must be stunned beforehand, which would nail the coffin of that "trick".
It's not the amount of Overcharge used or even the amount of turns that matter, it's the saving of time.
Truth is after you cast OFC, you need much more time to retrieve those OC and kill the rest SGs. You would end up normal attacking monsters because you cannot even maintain your SS after you cast OFC, and because there are only 2~3 SGs countered. Lefting the other monsters alive, I can easily retrieve my SS and the OC needed to cast vital strike.
OFC only empties Kotana's HP and merely less than half of the others. Then you would need at least 30~50 turn+ to kill the left SGs and get back to SS
Also anybody who puts vital strike on a hoveraction won't waste 1 single second.