Two of my friends main NIN. Each with different build. One is going for Crit-SkS and the other is going with common Crit-Det. The one with SkS always tops Det by 150~200dps. Because of the different build each is using a different rotation. Det is using the known rotation for NIN. While the SkS one had to do many tests to get it right (not many guides are available for SkS NIN). He also broke A12S dummy (Stone, Sky, Sea).

This is His try on dummy:https://youtu.be/XDGd9E9ce1w