I find trim dies to be tedious to use, but trimming a quarter inch off of a case with a hand-powered or drill-powered trimmer is also tedious.

The only one I used a lot was to convert .30-30 Winchester cases into .30 Herrett. Fine hacksaw (a coping saw?) then the file, but it seemed to distort the case mouth a lot, many needing bending back to "almost round" with a small screwdriver shaft or something before you could resize the case and get the expander ball inside.