A Subaru is unstoppable on winter tyres. I drive mine through deep snow past all sorts of stranded Mercs, BMWs and front wheel drive stuff spinning away their wheels and going nowhere. So for a feeling of smugness they are unbeatable. Add to that the safety implications of reduced stopping distances when below 8 degrees and there is a strong argument for them. The rally drivers would never do a stage on the wrong rubber so why would you drive your's on anything but the most appropriate tyres.
As someone mentioned above, there is no guarantee of snow, but we can be sure the temperature will go into single figures for at least 4 months. I bought a set and loved them, sadly my car is gone but winter tyres remain. They are Dunlop SP Winter Sport M3, 215/45 R17 91V, tread depth as new and hardly worn. Give me a sensible offer and they could be yours for this winter. Collect from Bournemouth area.
Alternatively someone sell me a really good WRX or STi pre '07 to put them on!