I like how the XenForo sprite icons are fresh and are not the usual icons from over a decade ago that you can find all over the place. However they are somewhat limited imo. I wanted to add in the User CP icons for each item to make it look less boring, but only a few of them can be used. Right now I am using other icons I found in the web, but they don't look like XenForo icons.
Whoever made the awesome Xenforo UI icons I hope he will consider making more for the User CP