I bought winter tyres for the first time last winter. I run a BMW, with all the rear wheel drive entertainment that brings. I never had any bother, in all the snow & ice that last winter through at us. Whether it was forging new tracks through virgin snow, or driving over week old stuff that had been packed down to sheet ice - the car just did it, accelerate, corner, brake, whatever. I picked up a mate who owns a 4WD Audi, and he couldn't believe how poised my car was, compared to his running summer rubber. I've got Continentals "somethings", and can't fault them. They'll be going back on the car this weekend coming (as apparently they work better than summer rubber when the temp is less than 7 degress, altho I can't verify that!).
I do also have Autosocks, and as others have said, they do work really well, as long as you don't stray on tarmac. And thats their drawback, they are an emergency use thing, at least in this country where the chances are you'll be back on Tarmac the next day - they're on-off-on-off, with much scrabbling round feeding them round the tyres, getting dirtier/colder/wetter all the time. The winter rubber is always there, just waiting to flick a bogey at any snow that does come down.
Sure, with winter tyres, you might want a spare set of wheels, but you can also pay somebody like Kwik Fit (other tyre thiefs are available) to store them for you, if you don't have space at home.