I prefer the MT in snow. I had both, and honestly, the A/Ts didn't clean well in the snow. The treads tended to pack. Come to thing of it, they were okay in all terrain, but never excelled in any terrain.
On slick/icy/rainy surfaces, the MT is pretty poor. The lugs have no siping, and they slide easily.
BFG just redesigned the MT and it now looks like this.
http://www.bfgoodrichtires.com/images/ts-dl/tires/large/mud-terrain-t-a-km2.jpg Looks more like a Krawler, thicker cords in the sidewall, but only in really large sizes (35"+)
Now, I know your not asking for other suggestions, but I just gotta. I have a set of 31" MTs from Pep Boys, called Definity Dakota MTs. These things are figgin' great! Its a MT that has siping in the tread blocks, as well as being studdable (great for snowy/icy areas). IMHO, best MT that could be used in snowy/icy conditions. While they are not 3-ply sidewalls like the BFG, they are still nice and best part is they cost $99 a tire, and it's buy 3 get 1 free. Can't beat $300 for 4 MTs.