Unless you live somewhere you never see temperatures around freezing, winter tires are worth the investment. The cost of an accident, due to losing traction or control, far outweighs the cost of another set of tires and rims. Plus, your all season tires will last that much longer, not being used year round. It also frees you up to buy a set of tires that you prefer for fairer weather, or run aggressive AT or mud tires in the spring-fall months. BTW, put them on steel rims to minimize cost and wear/tear on the tires to have them mounted and balanced twice a year.

I bought a 1999 4Runner Limited in Oct 2012, and live in Northern British Columbia. I researched tires obsessively, and ended up with the BF Goodrich KSi winter tires in the stock size 265/70/16. I probably would have gone for Michelin X-Ice SUV in the narrower 245/85 size as my friend runs them on his 2002 SR5 and loves them, but I got the BFG's for a song with only 400km on them. I have found that compared to Michelin M/S all seasons (not the newer version with the snowflake) that the stopping and starting on packed snow, icy roads, and deep snow to be shockingly different. In H2 (your normal 2WD mode, rear wheel drive) the traction for starting, accelerating, and turning is impressive. The main improvement I notice is on icy surfaces. There are times I have stopped at a store, gotten out, and nearly landed on my a$$, due to the ice that I had just driven across, and stopped on with no difficulty. The other main difference is tread flexibility at temps as low as -30 Celcius. The normal all seasons lose the flexibility, due to harder rubber compounds (which in turn give better fuel mileage and wear) at these low temps, whereas the winter tires are still flexible allowing the sipes and tread blocks to flex and grip the road.

I find myself running in 4WD without the center diff locked (basically AWD mode) which allows me to travel up to 100km/h (60mph) on any road surface. I only lock in the center diff for normal 4WD when on snowy roads and going less than 60km/h (40mph). With the AWD mode going, I have no difficulty travelling any roads, short of mud/sand, with my snow tires.