The "CODEX Exclusive" branding indicates that the update was modified to:

In the underground PC archiving scene, is considered the "Gold Master" of the pre-DLC era.

: This indicates a release by a prominent scene group that bypassed Digital Rights Management (DRM).

For the best experience, it is highly recommended to seek out the latest "All-in-One" or "Legendary Edition" builds, as they include massive quality-of-life improvements and dozens of hours of additional story content not found in v1.03.