The reason I like the options object is that it's easy to tell what is happening when the function is called. Compare, for example:

    updateToolbar({disabled: true});

with 

    updateToolbar(true);

In the latter case you don't really know what the boolean parameter means. The former call, however, clearly indicates that you want to disable the toolbar.

This is especially problematic when there isn't an obvious meaning for the boolean.

The options object also lets you easily add new options in the future (as long as they have backwards-compatible defaults) without changing a bunch of code throughout the code base.