I have a set of rubber ones as well. Obviously only usefull in certain situations, but come in real handy last year in the alps when I had to get a tossed in a pretend 4x4 with no diff locks out of the way so I could get up the road.
They also don't cause as much dmage when they go flying through the air and hit the tosser who you told to stand out of the way, but then decided to stand behind you anyway.
Obviously no use what so ever for bridging but much lighter to get out when all you need us traction on sand/snow.