Codex Chaos Space Marines (2007)

For 5 years we waited until our beloved ruinous powers appeared in 4th edition, after the most excellent "3.5" codex from 2002.

And then we got this...

The 4th edition Codex was a meagre beast in my opinion.  Sure, you could field a highly effective army, but for fluff, you had to rely on painting alone.
Because out where the Legions and their specific quirks and traits.  All you got for this version was a "vanilla" list where you could slot in the cults marines, but nothing more.

While it did contain a lot of background material, a large part "new" from the previous ones (mind you, the 40k story remained as good as stagnant until the current 8th edition), it well, just felt a like a boring book with just a heap of generic force statistics and points to play with.  Surely, it was an effective army back in the days, but heck... bland.

It followed the still in use format though, being first fluff, then an oversight with explanation what each unit is about, and then the actual army list.

In between you got the colour picture pages showing the army in all it's glory, and there is some nice paintwork in there...

It felt it was just made for tournament play to be honest...