С release notes туго. На https://linuxmusicians.com/viewtopic.php?f=24&t=15530 автор таки немножко открыл, что там "такого":Kernel with properly set up full RT preempt.
Included full development environment, Compile your own apps with pre-installed dependencies (for most included programs).
Source code tools GIT, SVN, BZR and build systems are already there.
Ability to compile with both gcc4.9 and gcc5.
Uses JACK1/Qjackctl not JACK2/Cadence (although you can change this if you want).
Harrison Mixbus Demo pre-installed.
Stuff Outside of Debian/KX (Polyphone, Shuriken, Simple Screen Recorder etc.).
32bit AVL has a properly working build of Ardour with WinVST Support.
Extra tools for managing Debian Testing (AV Linux Assistant).
Complete and constantly evolving User Manual.
Strong focus on Video production OOTB (Blender, Cinelerra, Kdenlive, Openshot).
Extensive Audio-specific Custom Actions built into the File manager (Convert Audio Files, Create SFZ or H2 libraries from Thunar).
Super Easy Network Sharing.
Prolly other things, but those are the most significant