I retired from tree work, and kept one of our stump grinders, thinking it was an easy one man tool for side work. It was, but I should have kept a chipper too. I wound up getting more take downs than stump work. It never failed, jobs always ran over on time because I was used to having a chipper. Handling brush is harder and much more time consuming than chipping. You can give away chips, nobody wants brush. Our landfill takes all brush and small wood free, but you still have to run 20 miles to get rid of it, and if you don't get there today, you can't work tomorrow till you empty your trailer. I have a dump trailer and it was a very good investment, but a chipper is just a tool I can't see anyone doing this full time not having. I rented a small Dosco, and 6" Vermeer, they are just too small for anything but a homeowner. The smallest I'd go with is a Vermeer BC1000, Brush Bandit in the 10" range, or an old 12" to 16" drum. I rented a small air cooled, 25HP diesel chipper that was rated at 6" but had a 10" feed shoot that worked great, but, I forget what model it was. When we were in business the Asplundh 16" was about the best machine going. We got about 20 years of trouble free use out of ours, general maintenance was all it got. Disc chippers do have more parts to fail, pumps, feed rollers, etc., but are much more user friendly. I used to rent a 10" Morbark and it was the best small chipper I ever used. The rental company I dealt with had 2 of them and I thought I was gonna cry when they sold them and went to the Vermeer BC1000. The Vermeer is a good machine, I just really liked that little Morbark. I'd rent a couple different ones and talk to the rental guys to see how much maintenance they take. If they took that much upkeep, with every "wingnut" in the world renting them, a rental company wouldn't be able to keep them. Good luck, Joe.