When comparing Xournal++ vs Logseq, the Slant community recommends Logseq for most people. In the question“What are the best note taking apps for UNIX-like systems?” Logseq is ranked 6th while Xournal++ is ranked 15th. The most important reason people chose Logseq is:
Logseq is a privacy-first tool for thought.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Advanced PDF annotation tools
Fill shape functionality, shape drawing (line, arrow, circle, rect, spline), shape resizing and rotation.
Pro Supports pen input from devices such as Wacom tablets
Pro LaTeX support (requires a working LaTeX install)
Pro PDF, PNG export
PDF Export (with and without paper style);
PNG Export (with and without transparent background)
Pro Grid and rotation snapping
Pro SUPPORT
Pro Plugins using LUA scripting
Pro Audio recording and playback alongside with handwritten notes
Pro Privacy-first
Logseq is a privacy-first tool for thought.
Pro Networked notes
Similar to Roam's technique of letting the notes flow with links to each other.
Pro Local-first software
Every topic is its own flat file. Nothing is better than keeping your data in the file system with an option of git source control or online backup.
https://www.inkandswitch.com/local-first/
Pro Daily journal is capture on Steriods
The daily journal feature allows you to quickly capture disparate topics under today's date and by way of tags make things organized and findable from any topic page.
Pro Open source
Logseq is opensource.
Pro Structured data over willy-nilly formatting
Lots of apps are too graphically flexible in how they allow content to be entered, placed, and formatted. They act like Word when what you want when authoring content is Markdown. Content and semantic structure, not graphical frills.
Pro Org syntax
Logseq support Emacs Org syntax out of the box.
Cons
Con Keyboard-driven editing/navigating is descent but average
It is only because I was a long-time Checkvist user that I say this. Checkvist has keyboard-driven controls which are in a league of their own.
Con Still in Alpha
Logseq is still in Alpha and is under heavy development.