how's this compare to CMUX?

EDIT: I'll probably ask this exact question everytime someone posts a new agentic terminal manager.

EDIT EDIT: looks like there's some form of companian app, that's kind of cool. Will have to check this out later.

Similar in terms of features. I'd see the most meaningful advantage is the user experience, I find myself working significantly faster with Saggar. Beyond the UI, monitor & quick run windows, and rich command palette, I think the way Saggar orients your activity around your projects (e.g. a git repo) is really intuitive over the workspace model.