The biggest one is the advantage of automatic spell check on any and every word you write. It will be underlined in red for you sighted people, and for JAWS users, it will say the word oddly. You can arrow back and hit your applications key (3rd key to the right of the space bar on a desktop keyboard), which is just like using the right click on your mouse. The keystroke is faster—try it out.
The next and most important for any JAWS user is the great accessibility and interaction with websites. Where they are problematic in IE, they are not in Firefox. Even if you do not know the h for headings, or ; for landmarks, you can easily TAB through content, slowly, but TAB through content to move through a page.
For more quick keystroke lessons go to the TAB on JAWS/Internet