It sure does help if you are at the point where you have no more traction on snow/ice and one front tire wants to spin while the other one just sits there. LSD will put power to both wheels........I can't see how this would NOT be a huge benefit on snow/ice.

 

I'm not saying it won't be, just stating that without it, my car performs excellently in the snow. The worst issue in the snow I find, is the ride height, not grip, and I use all seasons.