Actually, I'm pretty positive its possible for your gun to stick outside the smoke while the actual tank is inside it. Meaning that your output receives no accuracy penalty where as the input (from a hostile tank) does.
Currently smoke is 35 for 1 use - it is only useful vs schreks with their now expanded scatter angle, everything else still hits pretty accurately through it just based on physics
From my own experience, and I did use smoke pretty extensively at one point, it worked mainly against other tanks like the Panther/Tiger/PzIV. I think duvka made a video of my vet 3 sherman beating a panther (using smoke & field repairs) but can't find it.
Maybe they changed it though.