[silicon_ghoti]

Our drive base used worm gears with relative success this year, and we had no problems with them breaking, though we used brass gears which at first threw up brass shavings something awful, but eventually the gears became comfortable and deceased in their hurtful ways. (Had that continued any longer us on the electrical team would have cried.) On the subject of back-driveability, we were back-drivable, but only with great effort, this is because we used "beveled" (?) gears (again I'm electrical, so don't quote me on this) which means the teeth on the non-worm-gear gear meshed nicely, and probably kept them from breaking.