Pre-game faction VS. in-game faction. Which do you prefer?

jjjk29

  If there was an mmo centered around a player built/run world, (which the exception of the dev made systems, quests and city's) but was divided by two or more factions.  Would you rather choose a faction in-game; meaning you have to find your way out of the starter zone and make youre own decision on a faction based on the lore in-game.  Or would you prefer a pre-game faction selection along with youre character creation screen, based on only knowledge you gathered via the games website, wikki, or any other type of knowledge base.

  Simple question.  Elaboration welcome...