re: "...and which [snow tires] are the best?..."
I posted this in another snow tire inquiry, above:
"...there is nothing that can beat the Nokian Hakkapeliitta 1...."
The Nokia tires (Nokia was the original name before they split off the cellphone business) have been the winter rallye winner's "secret" for decades. This model, the "Hakka 1", is the best application to a Mercedes in original size.