My experience with snow tires on a Subaru came courtesy of my now-departed '98 Legacy GT wagon. Chicago was getting slammed, and my "all-season" Pirelli P7000s were not cutting it. I called around until I found a tire joint with Blizzaks in stock, and drove the car over.
Coming out of the parking lot, my first thought was "the salt trucks have been busy," because starting, turning and stopping were absolutely drama-free. The car just did what you told it to. It wasn't a question of needing to control excess speed, as much as it was that extra margin of safety that can be the difference between your deductible taking a hit, or a smooth, sure stop.
As I drove home, watching the other cars (including some Subarus...Evanston is quite the Scooby hotbed) slide around, and knowing how secure and sure-footed my car was, made me convinced that I will never go through another winter without snows on my Subaru. I put snows on my WRX wagon, and it was a fabulous car.
No matter how careful you are, no matter how much distance you leave, there will be someone who has been trying to get traction for a few minutes and now that they have it, aren't about to stop for you, the person who brakes too late for the intersection and slides on through, etc, etc.
The braking and turning aspects of snow tire performance are exceptional. And snows don't wear that particularly hard, unless you drive like a fiend in the dry. My Blizzaks got four seasons out of them (running from Dec. to mid-April), before finally showing significant wear. This year, I'll try some of the speed-rated Blizzaks.
IMHO, if you live where it snows, get snow tires. They're cheaper than your deductible, should you need them and not have them.