I use it daily for work. The core concept is a single time-sequential outline. Each entry in the outline is referenceable and can be included by reference in other pages. Pages are created wiki-style. Entries can have additional metadata. There is a “todo” system of metadata (that I don’t use.). There is a data log query capability. All content is markdown. The editor inlines images. Outline + markdown + inline images + wiki-ish system is a sweet spot for me.