How's it work on ice sheets on Mt. Shasta, f'rinstance?

They won't work that well on ice sheets on Mt. Shasta, especially as the slope angles increases. Also, I think these are best on tennis shoes or lighter boots, so you might not have the ankle support necessary for steeper ice with the shoes you'd be wearing anyway. But for low-angle snow and ice travel or work in icy conditions these things are amazing.

It will definately improve your traction. They certainly aren't going to grip like some of the other nicer crimpons on this site, but you shouldn't have any problem walking without sliding. The spikes on these still grip fairly well. If you're looking into more of a long journey/hike you might think about looking into something that is more permanent. But the nice thing about these is their versatility. They can be taken on and off without any hassle, and also used on different shoes.