My father used to cut his firewood on a cordwood saw behind the tractor, and never could understand why anybody would use a chain saw. I hated the thing as I was always the one taking wood off next to that whirring blade. With a good sized chunk I really had to be paying attention and brace myself when it came off the table to keep it from pulling me into the blade. When he passed away 4 years ago that saw rig was the first thing that we sold.
Lately though I've been thinking about how handy it would be, as I'm thinning a young hardwood stand and producing a lot of small poles, 3-6 inches on the butt and 8-16 feet long. At one time he had an arbor and 24" circular blade which he wanted to use for a saw table for his hit-and-miss engine, one of those projects which never happen. I believe that it's still down there, and I may claim it for my own. I have enough steel kicking around for the table, and several small engines so that powering it won't be a problem.