I don't use one much. I hate dragging the damn thing through a tree. Also, in TX, we have to paint oak wounds. If I can't get to it to cut it, I can't paint it (not quite true, but carrying around a paint head and string along with a pole saw is a nightmare). Not to mention, it's rare to see a proper cut that has been made with a pole (and I include myself in that, despite my best efforts to make good cuts). That said, I sometimes use a pole in elms or pecans, or similar trees that need weight reduction at the tips but tend to lack a good, high, central TIP. I stick a pruner head on it instead of a saw in these cases most of the time. And you can't beat a pole for pruning a section that looks questionable to climb but needs to be saved to keep a client happy.
As for injury, my worst cut ever came from a falling pole (I have a scar from a chainsaw, but it was coasting to a stop at the time and didn't go deep). I was descending, bumped the pole, and it came loose. As it fell, it snagged the back of my hand. It sliced through the skin and severed about 95% of the extensor tendon of my middle finger. For two months, I wore a brooklyn-bridge-like apparatus to hold my finger up so it wouldn't heal with the tendon stretched. I'm happy to say I have regained full use and range of the finger. But you better believe I'm a lot more aware of where my saw is, which direction it's hanging, and how I can stay out from under it. And I cringe every time I hear something bump into the pole.
I still think pole saws are useful and always have one around, but they have specific purposes and should not be used to compensate for poor climbing skills, IMO.
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