Reviewers mostly praise Mermaid Chart for turning text or markdown into diagrams quickly, with less manual layout work and strong fit for documentation, system design, team discussions, and developer workflows like GitHub and infrastructure projects. They repeatedly call it simple, flexible, well documented, and easy to integrate, with some saying it speeds up diagramming dramatically. The main caveats are that the syntax can feel clunky at first, some UI controls like text and border styling seem limited, and as a standalone paid tool it may feel less compelling beside bundled alternatives.