When comparing Org mode for Emacs vs Roam Research, the Slant community recommends Org mode for Emacs for most people. In the question“What are the best knowledge base systems for personal use?” Org mode for Emacs is ranked 3rd while Roam Research is ranked 17th. The most important reason people chose Org mode for Emacs is:
Org mode started out as a simple outlining/note taking app. Then each outline heading can optionally be a TODO list item. And if you desire, you can add SCHEDULE and DEADLINE dates. (Schedule being the date you'd like to start the item.) You can customize the TODO states to add things like DELEGATED, WAITING, BLOCKED, etc.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Can be as simple or as complex as you want
Org mode started out as a simple outlining/note taking app. Then each outline heading can optionally be a TODO list item. And if you desire, you can add SCHEDULE and DEADLINE dates. (Schedule being the date you'd like to start the item.) You can customize the TODO states to add things like DELEGATED, WAITING, BLOCKED, etc.
Pro Libre/open source
Pro Cross platform
Emacs runs on all platforms, Windows, Linux, OSX, even Android and IOS

Pro Exports data to PDF, LaTeX, HMTL and other
You can even build presentation or blog from your data

Pro Supports tables with formules (quite powerful!)
Pro Plain text data storage
Future-proof.
Pro Inline image displaying
Pro Free but copyrighted
Pro Fast interaction
Once muscle-memory sets in, can be much faster to use than a point & click program.
Pro Uses Emacs
Pro All apps
Pro In place page creation / linking with brackets or hashtags
Pro Rename a page and all everything that references it renames as well
No broken links!
Pro Each bullet point can be either linked to, or included in full in any page (including the page it originated on. Yay transclusion!)
Pro Shift click on a link pulls up the link in a side panel without navigating you away
Pro Each bullet point on a page is zoomable as it's own 'wiki page'
Pro Helpful slash (/) commands while editing for autocomplete, TODOs and more
Pro Easy page merging.
Pro Explicit linked references included on every page at the bottom
Pro Supports markdown
Pro Bi-directional links
Pro Graph overview allows you to easily see how nodes relate
Pro Supports in place datalog queries
Pro In place editing
Pro Supports hiccup syntax for HTML snippets
Pro A default place for "Daily Notes" means not having to worry where a new note *should* go.
Cons
Con Obtuse documentation
The documentation assumes a level of understanding of basic Emacs usage that not all users may have.
Con Complicated to get started
Con Difficult to use as a database
For example, if you need to quickly populate client details on quotes, unfortunately its easier to find, copy & paste.
Con Not suitable for normal users
Not even a majority of software developers can be bothered to use Emacs (or VI, for that matter).
Con PDF export can be difficult
Latex assumes you're a (compliant) student, have to do a lot of research to get what you want out of it.
Con Uses Emacs (for those who prefer vi, menus, etc.)
Con No mobile app
You can port Roam to Hermit, but there is no offline capacity.
Con No established pricing model, this could get expensive later
Rumored to be upwards of $30/month
Con No offline mode
The information can be accessed on the browser offline, but you cannot edit it.
Con Very expensive pricing model, no 'free' tier
For what still feels like beta-software, it's pricing model is very expensive in comparison with competitors that generally offer free tiers for example.
Con Forces you to edit with markdown, rather than wysiwyg
This issue is made worse by super basic formatting bugs, like if you want to for example unbold some text with control/cmd-b, it rather double-bolds it (e.g. it becomes bolded text), making the non-wysiwygness even more messy.
Con No vim mode
