When I lived up in the Pacific Northwest and lived on acreage with timber I had a couple of chippers over 30 years or so. Love hate relationship. The first one was a standalone McKissick 7 (or 9?) HP. It worked ok on smaller stuff but anything over about 2 1/2" would beat it and you half to death. Later I got a PTO driven model and ran it behind a couple of different tractors. It was better than the McKissick but it was still slow, noisy, and incredibly dangerous. I eventually settled on a procedure where the larger stuff got bucked up for firewood, and the smaller stuff was arranged in piles or rows, and run over with the brush hog. If I was going to do it again I would just rent one of the big self feeding models once or twice a year, or even better, have an arborist bring his chipper over and do it for me. That's what I do now.