My twopenceworth: Rhythm is one thing I haven't seen mentioned in the foregoing posts in this thread, unless I missed it. As a dedicated two-poles user for more than 15 years, I find that I can get into a good steady walking rhythm when I'm on the flat, be it tarmack, a track or a good trodden path. Without the poles I tend to walk very "untidily", with fluctuating speed and failing to keep to the straightest course.