Confluence

Real-time simultaneous editing
Ease of finding and organizing what I've written
Constantly adding new features
Integration with Jira and Trello is great, but also works as lightweight project management by itself

Honestly, they've fixed my biggest cons, like storage space (now you can buy a bigger plan) and they keep adding more things.
I think my colleagues would say there's still a learning curve, which is understandable, and I think Confluence has been changing the interface with more tips and features for new users (which is sometimes confusing for long-time users like me, LOL)
One big con is still the limited integration with MS Office. Confluence fully replaces the need for Word in most cases, so that's not a big deal, but I wish the Excel integration and/or the table functionality was better.
Also, printing is pretty tough when you have tables.

-No need to use multiple MS software like Ms Project, excel or even Word for documentation. Now I'm using a single tool for my Checklist, Requirement list, action plans, help guides, and testing strategies.
-I like how it is integrated with JIRA which is also one of the main tools we use at work. All Jira dashboards are available within Confluence which allows documentation to be supported by task.
-There are ready templates for creating different types of documents. There is an option to create hierarchy for documentation and link them to each other to avoid duplication.

-Right now, exporting of documents is only limited to Word and PDF file types. It would be better if there were more options.
-Adding the option to customize forms would be a convenient feature. Instead of only having the pre-build forms.
-It is also better if there will be more complex support for searching algorithms for discovery when searching, not just by typing the exact keyword

The software is very easy to use for its most basic features - as a place to create and store content. It is a solid tool for a knowledge base or even project management. Macros allow creatively in how content is displayed and linked or mirrored from other pages. Users can control permissions, visibility and see a clear history of changes - which can be easily reverted back to if necessary. Page trees make it simple to navigate complex "spaces" of information and the search functionality is robust. Overall, a great place to develop content for internal collaboration and future reference.

Although Confluence is a great place to create and collaborate on content, it has a few major downfalls that are a constant source of frustration. The biggest issue relates to users working on the same page at the same time. This is a horrible experience at best. Content between users is frequently lost or overwritten and you can never be confident in if your content will save successfully and not disappear. When Confluence tries to merge changes, it often will lose content or simply not work at all. The result is users ensuring that only one person is editing at a time, which is a terrible annoyance and slows teams down. It often causes teams to actively collaborate in another tool where this is not an issue and then simply link to it through Confluence.

Easy to use navigation bar per space (topic area) of store notes coupled with a range of text formatting and style features - Confluence is one of the best software tools available for notes taking! The inbuilt macros, linking page functions, mentions, comments and live editing all add to the allure of the Atlassian product range.

Confluence can be a steep learning curve due to the overwhelming amount of functionality available - including the permissions and access control clashes.