The main difference is that Chartbrew is tailored more for companies working with clients in need of dashboards. What this means is that Chartbrew has granular permissions on dashboard-level to allow the clients to explore the data, a templating feature to quickly create dashboards for new clients, and easy embedding to get any chart in your own product.
Not yet documented, but Chartbrew also has an API for creating dashboards from templates through its API. This will allow product owners to spin up a new dashboard whenever they get new users/clients in their platform.
User signs up -> New dashboard is created -> User is given access to the new dashboard -> Charts are made available in other apps
Another obvious difference is in the feature set that is more vast in the other two solutions. This is both a blessing and a curse. Some feedback I received was that it was easy to create visualizations because of the simplicity. I'm always improving on current visualization aspects whenever a client needs something more complex, though. I'm aware I would never be able to come close to the more mature solutions, so I'm serving other use-cases instead. Hope this all makes sense :)