had a three pair of Yaktrax and a couple other brands. none of which impressed me. they were "light-duty", mostly useful for city folks walking on icy sidewalks.

on the other hand, i've had great luck with Kahtoola Microspikes. these have serious spikes and they stay in place. they have been the only ones that allow walking across large sheets of thick sloped ice without slipping, and still stay in place!

warning: don't wear them on wood floors and expect to be able to walk at all. the spikes dig in and lock you in place.