I had a 15 hp DR field and brush mower. Actually cut down and chewed up 5-6 foot tall stuff just like on the commercials. I probably abused it a little, but I took out a couple of ~ 2 inch thick trees; I think the 15 hp was rated for 1 1/2 inch. In real heavy going there was a little vibration in the handlebars, but it wasn't bad. I say had, because the ex-wife took it. Fair trade, I can buy another DR ...