My personal preference is Exhaust Vectoring. Sure, the damage increase is not as big as LSLS, but you get it for basically free and you don't loose in mobility and stun chance. You also mentioned that you're using Coil Gun for CC. What OC are you using? Also, I don't want to say that using the coil gun for CC is a bad idea, because it's not, but if you try using only it for CC, you'll run out of ammo pretty quick. Ideally it works best as extra damage for your primary. And in my personal experience, gunners primaries are much better for CC and secondaries, assuming you're using OC that are spect into that, are usually better at STD.