kotor1 was alright how you could go back to being revan, but the fact that no one believed you, and just thought it was a joke was disapointing, you couldnt really go through the full darkside experience(untill the last minute - at the end where you cant even play anymore)
and if anyone has played star wars jedi knight jedi academy, knows the fact that if you go to darkside and the end, the jedi AND the dark jedi attack you, but if you go lightside the jedi assist and help you, and you fight against the dark jedi
it seems that in games, that you never truely get the full darkside experience, for either way your being hunter by the sith or dark jedi. so i think we need to be able to be on the side of the sith/darkjedi without having them attack you