FastMoneyPlaya

I've got Blizzaks on my Audi S5, and good all season's on my Audi A4 - both with Quattro. The Blizzaks will go through anything - I drove through multiple 12-18 inch dumps last winter and never had a problem - and the S5 is a lot lower than a GL. Drove the A4 with all seasons through 6-12 inches of heavy wet stuff last weekend and it did great. Where I find a big difference between the Blizzaks and the all seasons is on the highway when there's about 3 to 6 inches of grooved up slop - the Blizzaks seem to cut through the ruts better. Also, the snows seems to have a noticable advantage on steep hills - the all seasons tend to slip a little.

I suspect my unscientific Audi quattro analysis holds true for the GL - this is going to be my first winter with the GL on all seasons.

gedelea

You are talking night and day. All Season tires are a compromise so your stopping and maneuvering won't be as good as a dedicated snow tire. Choosing tires should really depend on what type of snow, how much snow, road type (hills, flats, etc) and your driving style. I love Hakkas or Blizzak type of tires if you are looking for the best performing snow tires. My E63 and M5 used to wear them and I'd laugh at the SUVs that sat in the ditches.