I do all my work with a drawing stylus and have never found the native Eraser tool to be useful. Instead I use Astute's Opacity Brush, which lets you quickly paint opacity masks for the selected objects.

I'd love to be able to access it by flipping my stylus over and eraser-clicking, but that only gets the Eraser tool.

Before the Opacity Brush came up I've had other thoughts for this - how about assigning the eraser end of the stylus to your favorite selection tool instead of constantly hitting hotkeys to switch to and from it, for instance?