BookStack is fantastic for having business users and not-so-technically-savvy IT users. It enables them to create a documentation they like in a visual way while still forcing them to adhere to logical structure of a document. It works fine even for more technical matters such as integration guidelines, especially when these concern some of the more obscure technologies. The exported docs are presentable but lack any interactivity. Where it lacks is generating heavily technical documentations. Heavier REST or GraphQL integrations should for example be documented through other means. As for developer documentations, there are definitely more suitable alternatives, also.
If you want a customizable solution that can be adapted for just about any scenario, I recommend using Notion. If you need a solution that's easy to share with people outside your organization, Notion is great and allows individual or team permission-setting. If you want a turnkey solution, Notion might not be the best since it requires a fair bit of set-up. There are templates that can be purchased to handle this, but I haven't found them very helpful.
I use Notion on my personal tablet, and unlike on the computer, I have a lot of difficulty editing backgrounds, GIFs, and page dividers. It's not as user-friendly, and often the elements end up cut off or misaligned, which is frustrating.
While the current calendar feature is helpful, I'd love to see more customization options. The Google Calendar style isn't always ideal, especially for tasks without specific times or for ongoing projects that require daily maintenance.
It would be fantastic to have more flexibility in customizing Notion pages. For example, I'd love to create planners with the freedom to add illustration boxes, stickers, or GIFs without being restricted to a fixed layout.
Very easy to use (I learned how to use everything on my own) and I was able to set up an entire ecosystem without any courses or other tools. I often say that Notion is like Lego for adults, because there we can use all the available tools to create a multitude of things, from funnels to projects with calculated deadlines and tags.
Confluence, having only a slight advantage in terms of features compared to BookStack, really only makes sense to procure as a part of the Jira bundle. It requires much more maintenance from my experience and does not really deliver any extra value aside from the very strict certifications like HIPAA. DokuWiki and MediaWiki both provided way too much in terms of customizability, not really focusing on the business need. Of course, MediaWiki was conceived for a whole different purpose but is very often seen being used for both internal and public documentation delivery. DokuWiki did not provide the authors with the user-friendly environment that BookStack has and integrated most poorly with LDAP. As for OneNote, which was used for support docs prior to BookStack, it provided the authors with too much of a user-friendly environment, rendering the product of their work very inconsistent. Also, the sharing model was either peer-to-peer or within Teams, neither of which made it easy to audit and supervise.
The company uses both Notion and Trello within the company. Notion is more for North America employees while Trello is used between Operation team overseas and in North America. Sometimes it's a preference of how the tools look like for project management. I would say both Notion and Trello are nice tools and serves our needs.
Spillover within Business IT staff up, nearly double substitutability. This is through the ability of a support technician servicing a different product to find a guide describing how to solve the more frequent issues the way a product lead would do it.
Time to draft and publish a documentation down some 20% compared to previous solution.
OpenSource that integrates fine with enterprise-grade software and somehow even passes security audit. 20 times cheaper to implement compared to Confluence, almost free to maintain.