Snowchains are awesome, I bought some from the Halfords bargain bin for £5 about 4 years ago, and literally 2 days later we had massive snow!
I had the Vectra at the time so I put them on the night before and used them to get to work the next morning. Being self employed, it takes a lot to stop me working!
I was unstoppable! All the main roads were slush and gridlocked so I took the uncleared country route to work and it was the best fun! They gripped incredibly well and also worked for braking. Had some plonker behind me in a BMW X3 who thought he was the king of the road and was all up in my mirror to begin with, but even he was struggling. I left him miles behind sliding all over the place.
I even managed to get down a steep hill near work (next to the John Nike Ice Rink for anyone that knows Bracknell) that was in the process of being closed to traffic even as I descended. The workman guys were very impressed as my little Vectra made it down the hill under total control!
One note of caution though - mind your alloys, the chains can rub the face of them if the metal comes into contact with your wheel. My alloys were knackered anyway, but the marks the chains left were always there after that. I would consider making some plastic discs to put under the chains to prevent scuffing.
Trouble where I live is the roads are cleared so quickly they don't stay on long.

I've just now put them in the boot in case of emergency.