mac40k said:
The Chapters that have their own Codex are the ones that have unique organizational structures and the most fluff to work with so far. Most of the others are some flavor of Codex (read Ultramarine) Chapter perhaps with a slight twist (more psykers, more bikers, more flamers/meltas, etc.), but not all that different from any other Codex Chapter or a successor chapter of one of the other iconics.
This statement is so not true. Let me list a few of the lesser known Chapters that are known to have "unique orgizational structures" or are unique some other way: Black Dragons, Excorcists, Relictors (still loyal in the current DH/RT timeline), Iron Snakes, Iron Hands, and Mortifactors. Beyond that there are many Codex adherent Chapters that have peculiarities that make them stand out. In fact, both the Blood Angels and Dark Angels are basically Codex chapters (of First Founding Chapters the Iron Hands are MUCH MORE divergent in the way they operate). They aren't any more "unique" than the untold Chapters of the Imperium, they simply have more developed background material.