One of my major issues with playing an Origins character is that their personalities are already quite defined to us; the notion of playing as Lae'Zel or Astarion and then choosing actions which are contrary to their personalities seems a bit contrived to me, assuming that Origins characters won't be railroaded into decisions which reflect their demeanours. In essence, you could roleplay a selfish or 'evil' Origins character as a 'good' character and that just feels strange, mostly in terms of having a grounded and believable game.
