I just use a $30 brush axe from ace hardware. It can handle anything from 4" saplings to thick briers much easier than any thing pictured. Does it look cool? Nope! I always have one in my truck when deer hunting. I just mark a trail to the deer with surveyors tape. Go get the brush axe and cut a trail to retrieve the deer. Buy the model with a hickory handle. You will get 10 years of use out of it. I just use a belt sander to keep an edge on it.
I have respiratory problems and it takes a healthy man to haul and pile the brush as fast as I can cut it when clearing underbrush.