I posted my observations on another thread regarding my demo of the Dingo stumper. I ground a 3 ft. dia. stump and it ground about as fast as a Rayco Jr. What I did not like was the wheel is mounted sideways and it threw chips all over the place, even 50 ft. away. Unless you are going to set up 8 ft. high plyboards around the grinding area, I personally would not buy it. I am getting a Terra Power attachment, go to their website to check it out. It is scheduled to be shipped next week. I'll post results after I get it. I have a Prowler mini skid, 14 gpm flow. The Dingo has 12, some others like the Thomas only have 8.5, you need at least 10 gpm to run a grinder.