The whistle on the ferro rod works, but it isn't super-loud. I would prefer a Fox 40 Micro or something similarly loud. As a backup to a better whistle it's adequate. This component is easy to remove but secure when in place; Leatherman did some clever packaging here.

I tested the sharpener with a couple of passes on the S30V blade. With some patience and care, it can be made to work and is definitely better than nothing. A dedicated pocket sharpener would be a lot easier to use and give better results; in other words, it's an adequate backup. The unlocking lever for the inside bits also keeps the sharpener secure.