I use a single pole; partly as an aid to balance and partly to ease the load on my knees going up- and downhill. I originally used an ice axe for these purposes but since my climbing days are largely behind me I have settled on using a single, lighter, twist-lock Leki pole with a hand-grip similar to that of a cane. It serves me quite well. To me, the thought of trying to manage two poles in places like talus slopes and brush, and not having a free hand when needed, is a bit intimidating. YMMV.