One of the guys in our group last weekend had a set of Traction Jacks and broke one side in half on our recent snow wheeling trip. He was trying to get a little more traction going up a stream crossing where the water had undercut the snow and made a steep ledge to crawl up.
Another guy had a two pair of maxtrax which we had to put into use when he drifted out of the track going up hill and buried himself up to the frame.
When he drove over them one got grabbed and stuck vertically down in the snow. It was like the sword in the stone with everyone looking at it and giving it a tug and then declaring it stuck before the next guy gave it a shot and failed as well. Ended up digging it out to extricate it.
Personally, I have a set of waffle boards and they work good every time I've had to use them, once for bridging a low spot to keep the side of my truck out of the rock wall next to it and a second time in conjunction with an x-jack to free a rental jeep that had buried itself to the bottom of the sills in sand: