Taking the buff at the site of power in ammer gives you following bonus stats.
<img src="https://i.imgur.com/JhFTTYJ.png" alt="JhFTTYJ.png" title="JhFTTYJ.png" style="font-size: 0.8em;" />
Only, it does not seem to affect the one I am most interested in, Anger.
<img src="https://i.imgur.com/8VYk1Yd.png" alt="8VYk1Yd.png" title="8VYk1Yd.png" style="font-size: 0.8em;" />
Is it because 2 different terms are used for the same purpose stat? Anger & Fury.
Posting this to link through to support - also so that people know that this has been reported now.