Someone gave us a petrol-engined one, not sure make, which looked quite powerful, but really did not do a good job and took so long to do it. I think the smaller or even moderate sized ones really are not much use. I am thinking it might be better and cheaper to save up all your sticks in a pile and hire a big one from the plant hire place once a year. Same with hedge trimming - the good Stihl hedge trimmer on which you can angle the blade at rightangles to go along the top of a six-foot hedge while standing on the ground costs several hundred pounds but 30 odd quid for a weekend hire, and no worry of maintenance/repair etc