For example, moving around by using the search feature (at least a well-designed incremental search like Vim or Emacs) is more efficient for longer distance moves (e.g. more than a couple of lines)--it's faster and, more importantly, takes less thought and context switching.
When you have to move to a distinct part of your text file, chances are you know what the content there is. With a command like /, you directly turn that knowledge into efficient movement. With the arrow keys, you have to leave the home row and do a bunch of movements to get where you're going. You have to figure out how to turn the word you want to go to into a bunch of arrow actions. It's even more difficult of your target is off-screen.
Ultimately, a rich set of movement commands you can access without moving your hand is going to be more efficient than using the standard arrow keys. This is particularly true for somewhat semantic commands like moving by block or expression or moving to a word (the command in question here).
Ideally, you want to move around faster with less context switching. Keyboard-oriented editors like Vim and Emacs are much better at this than any other editor I've seen, as long as you learned how to use them properly. This really makes the learning curve more than with it.
