...an accidental power-down could be devastating.
And with this thread being largely about just "how devastating" a sudden power-down situation can be, I can only offer my experience of never having lost a file or corrupted a directory by doing so. That holds true for my SE/30 running System 6.x and 7.x and 8.x, with floppies and/or hard disk running (and not ejected). Perhaps some will call me lucky, but that is my honest experience. Of course, I do not recommend flipping the power switch off when you have the means to eject a floppy and or perform the Shut Down command. But you need not lose sleep if it happens once and a while. Besides, we all have backups, right?