Chatted with a retired taper last night at the diner near the yard...
He was in the trade back when they still used paper tape and mud you had to mix yourself from powder. Said he never once owned a banjo, just a 6 inch knife and a hawk. Made me wonder if all these fancy self trimmer heads are really saving time or just making more work...
You ever try to fix a self trimmer head when the blade gets jacked up on a rock? In my experience those things are great until they ain't, then you're spending half a shift getting the head unjammed. I keep a couple old school manual heads in my truck for when the fancy stuff gives me grief. Your mileage may vary but I've found the powder mix tape holds up way better in wet weather too, less stretch and sag. Those old timers knew what worked even if it was slower.