Old saying still true.
Don’t take a slim jim to a weed whacker fight.
I'll use my brush cutter, never needs reloading trim line. I was trimming the 2 and 3 foot weeds on the hill behind my house, and the weed whacker was using up too much trim line. Switched to the brush cutter, much better. And even better was switching to the pressure washer which quickly knocked down weeds, ivy and brush especially through cyclone fence and around rocks. But the brush cutter is very portable, and the multiple steel blades would quickly cut down a thief.