I'm surprised you've given up on Kemba so quickly and I'm doubly surprised you'd want to do a "player vs player" after the Hendo thread.
Sessions is a subpar defending average PG who has traditionally done better coming off the bench vs. starting. He's better than DJ but that isn't saying much. Just like DJ he was given the keys in MIL and they ended up letting him walk vs paying him. He's very good at driving the ball and has a decent midrange but (except for a small stretch in LA) can't shoot beyond the arc.
He might end up being better than Kemba but his ceiling is pretty much known. Kemba's is not. Since we're striving for something more than a 1st round exit give me the younger guy and let him show what he can be.