Which one? It has 7 different UI paradigms you can choose from.
Personally i like the "Single toolbar" UI, it only shows a menubar and a toolbar with the most common stuff, which i find a great balance between minimalism and discoverability.
Though i only use like 1% of LibreOffice's features - and really only use Writer (which i mainly use as a dumb rich text editor) and Calc (mainly for a few calculations one could most likely even do in VisiCalc :-P).
Personally i like the "Single toolbar" UI, it only shows a menubar and a toolbar with the most common stuff, which i find a great balance between minimalism and discoverability.
Though i only use like 1% of LibreOffice's features - and really only use Writer (which i mainly use as a dumb rich text editor) and Calc (mainly for a few calculations one could most likely even do in VisiCalc :-P).