The new version puts the Mac Pro's processing power to the test.
The update is intended to make the most of the performance improvements of the new Mac Pro. This means 1000 audio and software tracks and five times the number of plug-ins can run in a single session, which is especially relevant for large-scale projects like film scoring. You can also run 1000 auxiliary channels and 1000 MIDI tracks, plus there's support for 12 sends per channel strip.
A more relevant improvement for users working on older devices is that the track freezing function now actually frees up CPU. You can also now create your own mixer templates, plus there's a new de-esser plug-in for taming sibilant vocals. The update only supports 10.13.16 High Sierra and up, meaning Sierra users will need to stick with the old version.
The upgrade is free for Logic Pro X users or $199 from the App Store.