I feel there are still quite a few icons missing, but I imagine they'll be rolling out soon enough. Just switched from Material Icons, I love the style of Unicons, but some core ones are missing.
The bell (mentioned above), a color palette icon, some icons displaying content (such as text, the standard "Tt" icon we always see), just to name some from the top of my head.
I do wish that icons were organized a bit better in their categories, such as "comment-slash" and "commnet-alt-slash" (typo there btw) being in User Interface rather than Chat, with all the other comment based icons.
All in all, love the icon pack and font, it's very clean