Thinking is inherently nested (topics and subtopics, key points and supporting material etc), whereas classic documents are linear.

Outliners are better than flat word processors for gathering thoughts, reorganising them, and alternating between overview and focus.

Apps like MS Word and Pages often have reasonable outline views, supporting collapse and expand, but their depth of nesting (indentation) is typically limited to 9 levels.

OO3 allows arbitrary levels of nesting, is fast and responsive, and exports to (and imports from) OPML - a common currency of many apps, including mind-map software, that work with hierarchically structured text. OO3 outlines can also be read straight into hierarchic diagrams in OmniGraffle.

In short, text is linear, thought isn't. Outliners make better thought-processors than flat text editors do.

The core of what makes OO3 the best in its class is that it combines nesting/collapse/expand/hoist etc with multiple fields/columns.

(That, and, of course, its rich and well-crafted scripting library).

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