A few things to think about.It weighs 175 lbs they say,on the side of a bike that would be tricky on rough or sloped terrain.Sharpening all those blades would take some time.It looks like it only cut some of the brush and just pushed some aside.
I didn't like where the guy reached out with his arm to push brush away from the blades.I can also see the odd big brush getting jammed between those blades.
At the price I would have to try it out before buying.
It is a novel idea for sure. as stated above, watching from behind the lower stuff is still there.
i guess price is all about how many buy it.