I am looking into a new trimmer(straight shaft)to use as my primary trimmer. My Ryobi( ahah, no laughing)curved shaft is starting to cause backache. I'm 6'4 and need something comfortable and have sampled several. The echos have the most comfortable grip and seem to feel well for upright trimming. Any other opinions? Also, when you trim do you have better results trimming in the direction of the rotation of the string or the opposite direction?