I haven't followed each and every codex as closely for the last several years, but since their inception the Dark Eldar seem to have always been a bit problematic. I get what they were trying to do, bring back the "Eldar Pirates" of the Rogue Trader days before the Craftworld Eldar were really fleshed out, but even today it still feels like the back-story and how it relates to their force organization is still poorly integrated... Space Marines, Eldar, Orks, Guard - those are all pretty solid, but Dark Eldar still seem to be one of the red-headed stepchildren of the range... Even Tau seem far more thematically unified at this point...