I have both styles and I just got done edging my entire lot - both sides of the fences on the 5 acre part that is fenced- with my Ryobi curve shaft trimmer. I also have a straight shaft Echo for but for comfort I prefer the curved one. The straight one is better at the heavy stuff and I can get overgrowth under trees easier due to the longer reach. Fortunately I don't have to trim the pasture parts of the lot - horses do that well enough lol.