The only thing is, you have it for life(it will never degrade), and how much the AI can potentially affect your mind and body(even without you asking it to) depends on how advanced it is. For example, something like, the IOS' Siri would not have any control over your body, it is not advanced enough to override your will, and what you could do would be limited to stuff such as google searches, and the like. But something like Cortana(I'm sure we all know about her) would have large amounts of control over you. Insane amounts of computing power, turn on your adrenaline at will, sprint at 30mph, then feel no repercussions because you could turn off the pain of your muscles tearing away from your bone, massive amounts of multitasking, dual weld a set of handguns with superhuman accuracy, write page one of a college essay with your left hand, then page two with your right. But this comes at a cost, your AI could go against your will, potentially take over your body to do what it deems fit(think, extreme sleepwalking) but you will regain control once you are concisious, and if the AI can't sleep, you can't sleep. What would you do? If yes, what kind of AI do you want, what personality? Cortana from Halo? Omega from Red vs Blue? Hal 9000? Siri?