When comparing Letterspace vs IntelliJ IDEA, the Slant community recommends IntelliJ IDEA for most people. In the question“What are the best Markdown editors for OS X?” IntelliJ IDEA is ranked 23rd while Letterspace is ranked 32nd.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Full featured iOS app
This was a iOS first app and that is clear. Great swipe bar interface on iOS.
Pro Simple, yet powerful interface
Keyboard shortcuts for basic text formatting. A few theme options. Full screen mode and swipe gestures.
Pro @mentions and #tags for easy organization
Pro Advanced Markdown support
Features Markdown support that many other text editors don't; such as Todo's ( -[x] ) and Strikethrough.
Pro Great Java Support
Pro A good editor for test-driven development
IntelliJ IDEA is really easy to work with when it comes to test-driven development in Java and JavaScript/TypeScript.
Pro Great JavaScript support
Pro Markdown support with preview
Pro Supports PHP quite well
Pro Great TypeScript support
Really good support for importing classes, libraries, etc. into a typescript class. Making it easy to do TDD.
Pro Good BASH script support
Pro Angular CLI support
Pro Made by developers for developers
It can make one more efficient, but also can get one way too used to shortcuts, autocomplete, and easy debugging.
Cons
Con No in-app Markdown preview
You can export to PDF or HTML with formatting, but no preview in the Mac app.
Con Is not free
But it does have a free version (Community Edition).
Con Heavy
Consumes more resources than VSCode etc. But depending on your use-case, it can still be worth it for the benefits you get with this editor.
Con Autocomplete does not work while IntelliJ is indexing
But this, in general, is not much of an issue. Usually after npm install, etc.