Two tracks in parallel
Deep notes, reading highlights, tech drafts → Obsidian on disk.
Shared docs, tables, light PM → Notion with AI inline when I need a paragraph expanded.
I sync with links and occasional exports — one tool for everything usually means mess.
When Obsidian wins
You want graph links, plugins, and files you own outright.
AI via plugins or external tools — I outline first, then ask AI to expand one section, not ghost-write the whole page.
Backup is trivial: copy the vault folder or push a private git repo.
When Notion AI wins
The team already lives in Notion; AI is a small add-on.
Summaries in databases, meeting notes, CN drafts from EN sources — all in-page.
Offline/local-first is weaker; I export PDF before flights.
Vs chat assistants like Pi
Chat tools are for quick questions; knowledge bases are for stuff you re-read monthly.
I brainstorm in Pi, then file conclusions into Obsidian or Notion.