the GTI is pretty good in the snow.
my 94 ford taurus was better, and so was my 95 buick lesabre. the problem is the center of gravity is too high and the wheel base is too short so your going to get some inevitable slippage.
however a good driver and good tires really make the difference. VT winters are brutal and unplowed. i had a line of cars get stuck on a hill, and instead of getting stuck w/ them, cut the wheel, feathered the gas, and fishtailed past all of them at about 7 mph. i should just say, i made it and they didn't.
but honestly, the traction control works great, but there is too much power to the front, and the open diff is REALLY noticeable. it's almost frustrating sometimes trying to build up speed. my buddy would just shoot out of parking lots in his WRX, and i'd be behind him spinning w/ my exhaust growling trying to keep up (not happening).
i should mention when you do oversteer it's rather easy to control in a GTI thanks to the great steering assist/electric steering motor. i still get goosebumps thinking about an accident i avoided 2 winters ago, where i had to swerve around a forester that backed into the road at 35 mph (doesn't sound fast but it is fast when your brakes don't work).
so cliffnotes: it works. it's not fast, it's not that fun. but it works.