The PDF version of this codex became an essential tool for players during this time. It allowed for easy searching of Stratagems, quick reference of point costs (especially after the Big FAQ updates), and army list building on tablets and laptops. However, the book itself is remembered for two distinct phases: the struggle of the launch index, and the glory of the codex proper.
The codex reinforces the Grey Knights' status as the Emperor’s "final gift" to humanity—a secretive brotherhood created from his own gene-seed to combat the daemonic threat.
Here's a brief summary of what you can expect from the Grey Knights 8th Edition Codex: