I see more bad happen to horse teeth with the power tools, than would happen with manual work when Dentist gets tired, checks teeth progress more often! We have some big name horse Dentists, both Vet and Dental qualified, charge an arm and two legs for cost. Horses have issues after, teeth die from being too hot with the power tools used too long on it. Horses ALWAYS need sedation when power tools are used.
I try to stick with the manual floating, have enough experience at seeing GOOD floats, the manipulation of jaw to test that work is completed well, that my horses get good work done on them. Dentist/Vet does do the WAYYYY back teeth and gets them nicely smoothed by reaching in there. I watch him do it, he points out problems when starting, what he did when finished, horse is NOT sedated and stands just fine. No need to “recover” from the work.
I don’t think the “extras” sold by the power tool folks are truly needed, just and excuse to charge more in most cases. Bit seats are a big one, grinding off tooth they should have left alone.
Power tools do take off too much, way too quickly, and as others mentioned, cause a lot of problems with teeth too short. There just is no “Putting it back on the tooth” tool available to fix the incompetent tooth butcher’s work for the horse.