Since LibreOffice 4.1 there is the Sidebar as a experimental feature. While devs work on improvements and stabilising for future releases, I mostly avoid that Sidebar :) Meanwhile many people are positive about the nice looking feature... Well indeed it shows nice. And it shows huge...
You may get the feeling here that I'm not so happy with the Sidebar? Indeed! I'll explain why. And of course will try to give a shot about a maybe possible improvement.
Reasons why I'm not too happy is first because it eats space. Double: most of the formatting settings offered are directly available in the formatting toolbar already.
So for me, two reasons to dislike the Sidebar: for eating space and for promoting bad habits :(
Now, before bringing a suggestion, as a side step, a way in which the Sidebar can bring some sort of fun: when opening the Navigator both apart and in the Sidebar, one with only headings shown and the other with all other content.
Then for a maybe possible improvement – I try to bring this careful, because ideas are often easily written down, and hard to realise ;)
From my objections with the current implementation, it's clear that I would rather see support for the use of styles. So I mocked up a little version with various style categories shown at the same time. And maybe also something can be done with the presentation of the font, as is the cast in the list Select Style.
That's all that there is for now.