I've yet to run a Black Crusade game, though I'm making preparations at the time of this post.
My players are all veterans of many game systems, and are very familiar with the 40K RPGs.
Something I have recently become concerned about (in regards to Black Crusade) is the defining concepts of characters being pushed aside for the sake of game mechanics and their rules benefits. In Dark Heresy, Rogue Trader and Deathwatch the progression of a character's Skills and Talents is defined by Rank, with access to various abilities being limited by this restraint mechanism, as well as by GM approval in the case of Elite Advances.
I realize the Alignment mechanism is meant to take the place of the Rank mechanism, but my concern is that Players may run roughshod over this mechanism in pursuit of Characteristic Advances and combat-focused Skills and Talents over concept and RP. Combat is a prevalent feature of Black Crusade, so it's natural a Player would want to decrease a PC's mortality percentage, but this is also a game of personal glory- seeking one upmanship, gloating over who dealt the most Damage, or who dealt the killing blow, and so on in the quest for the favours of the gods.
I'm asking for GMs to share their thoughts on this subject. I realize every gaming group will have differing dynamics and styles, but have any fellow GMs noticed a "cookie cutter" pattern to character progression, whether it be early, mid, or late PC progression, and what have GMs done, besides sitting down in discussion with the Players pre-game, to discourage Xerox copy PCs.