Dad bought a new HD40 Woodmiser in '88. It had a 21' bed, so as to saw 20' logs. It was the berries..!! He sawed over 160,000 BF of lumber on it in 9 years, before his passing, he counted, and looged every job.. Most of it was custom work, and never advestised. Keeping the machine, and blades in top shape is the key. If you've ever been to where they demonstrate the Woodmiser's, and watch them saw a slab off maybe 3/16" thick, they are amazing. He would do that on his, if someone stopped to see how good of work he and it did.
He did a lot of work for a custom builder that built high end houses. He would tear down old barns for the beams, and have Dad saw the faces off the timbers for VERY expensive paneling, then saw the rest for hardwood flooring. He even sawed out beams/timbers for another builder, who wanted to build his own pinned type barn.
He also got the automatic blade sharpener, and setter. Again, keeping the blades sharp, and proper set are the key to quality sawn lumber.
You'd be surprised the logs that were given to him from someone building a new home in a wooded spot. And I'm talking cherry, walnut, poplar, sassafras, etc.
He passed in '98, and mom sold the mill 5 years later, as I had 5 years to work yet, and no time to run the mill. There's probably close to 10,000 BF of cherry & poplar still stacked & stuck in the barns, plus several stacks of pine & white oak.