I recently went to work for a different company and my new boss uses curved shaft weed eaters. POS homeowner single stranded echos to be precise. And I cant seem to get them down to save my life. I have about 3 years of experience with the stihl FS100x and felt that i was more then profficient with it. I even used it to vertically edge the sidewalks and driveways. But now that I have to use these echos I have a hard time trying not to scalp the yards up and an even harder time trying to edge the beds. And forget even thinking about edging grass to concrete with them. Not to mention It KILLS my back i mean ive never had back problems untill i started using the cirved shafts. Why do they even make them? Do ANY of you guys use curved weed eaters? I feel like everytime some one sees me using the weedeater they're thinking, "look at this idiot using a homeowner weed eater."