Like you, I've toyed with the idea of not using them as my pack got lighter. (I used a single staff, then two poles, when I was carrying a 40 pound pack for a weekend; now I'm at 20.)

However, I find that I always take them, and that they're always in my hand. They help establish a rhythm, and they help push aside brush, or knock down cobwebs (if I see them in time.) On uneven terrain, or crossing a stream by rock-hopping, they help keep my balance - unlike Redford and Nolte in Walk in the Woods, who fall into the stream with their poles famously strapped to their packs. On downhills, they're handy brakes, and on almost all surfaces, they do help absorb some of the pounding my old knees would otherwise take.

I've used them as tarp poles, but nowadays, with two pound tents, they are strictly a single-purpose item. My current preference is a pair of Black Diamond Trail Ergo Cork poles.