LibreOffice does look a little more modern thanks to its larger icons and leaning towards subtle pastel hues, but it's nothing that'll affect your everyday work. The functional differences are very minor for example, the sidebar in OpenOffice Writer is open by default, whereas in LibreOffice it's closed. LibreOffice and Apache OpenOffice are almost identical. Both software suites offer plenty of user-made designs to download, but LibreOffice's selection of pre-installed options is far superior to OpenOffice's. If you often need to make presentations, LibreOffice has the edge in terms of the number (and quality) of slide templates available.
