I find it slows down camera wake time by a split second due to the boot flags, so I don't use it all the time. But because it's so easy to enable/disable, I have it on my card and take half a minute to enable it whenever I want to do video.
For photos, it's only really worth it for the intervalometer. There's also focus ramping for doing focus stacking, which I've yet looked into.
For videos, it's a must for focus peaking along. The shortcuts are also brilliant for adjusting audio on the fly.