Man, I gotta disagree on the paid-for-itself call. A $340 used machine that runs 68 holes in an hour is nice, but at a buck or two a hole you're looking at maybe $70 to $100 of value, so it ate into the loss from a job you underbid, it didn't wipe it out. The real lesson here is you quoted too low, because a used Castle at that price is a good find but it won't cover a bad bid. Still, no tearout on maple is no joke, so I get why you're happy with it.

Read a thing from some old logger on a forum saying he sizes his hinge at 80 percent of the tree's diameter, not some fixed number like an inch. Been trying that out lately and it cuts way cleaner, the tree holds on longer and goes where you aim it. Diameter and lean make way more sense than just picking a number and sticking with it for years.