The SI is different, and that is what makes it more interesting. Unlike the SW, who gets all the fan fare and arse kissing, the SI is treated like trash, with no expectations for success. The Overseer in charge has open contempt for you, and is constantly putting you on suicide missions, hoping you will die along the way; every time you come back successful, it makes him angrier, and more determined to kill you. Eventually you find out that you are not a nobody, and that you have a destiny to restore what rightfully belongs to you. And just when you think you have finally achieved something, you are betrayed by you master, and have to defend yourself.
The part with the overseer is defintiely awesome. The story starts great. There is a reason you want to succeed, just to show this guy that you can and that he has no clue.
But afterwards, the story seems to drift.