I have all but done away with my hedger tool and my chain saw for most jobs. Hedger teeth are plain steel and dull quickly and then tug and tear rather than cut. Same goes for Chain saw chains, dull in a snap and take forever to re-sharpen... Simply put on a high tooth count CARBIDE Teeth BLADE on your string trimmer weed whacker and voila. I have an Echo and what a dream this tool is now. I found some awesome blades for even cheaper than stihl or echo plain steel blades here:

www.carbidebrushcutterblades.com

And brother, they work. Tree trimming and pruning and knocking down black berry bush brambles is a breeze on my acre an a half.