I use GCC, so I'm in the same boat. If you are only hipfiring, I see it as a case by case thing. I'm more likely to use it if I'm silenced, since there is more time to make the accuracy count. Also, I never use SS with the Ivana.
It works, With SS i need less bullets to kill someone from way across.
Big x2 on this point. Doesn't matter which control scheme you use, it still holds true. Those with brlliant connections can probably get by without it. I struggle to kill long distance without it myself.