I love these things!
I bought a pair of Yaktrax Pros last winter when the trail I hike on became too slippery to hike in just boots. These things literally saved my butt. My friends would slip and slide on the descent, grabbing trees and branches to stay on their feet. I can just walk like normal - they don't slide at all.
I found myself wearing them just to walk to the mailbox because the streets where I live remain snowpacked for most of the winter. It seems like the worst falls happen when it's least expected - walking the dog, etc.
I bought the Pros because I knew I would be wearing them often and I wanted the strap over the instep. For the small difference in price, it was a no brainer.