I'm a big rondo fan. My problem with Payton's game is that the other parts of his game aren't good enough yet to make up for his offense yet. He's been pretty good on D but he struggles with the PNR and gets beat on back cuts too much. Most people haven't watched 20 magic games this year. Again I'm pointing out that he really isn't performing that well like you say. I think he is going to be really good but he will need time. The rookie ladder is a joke this year BTW.
I'm a fan of defense which is why I like him but he lacks defensive awareness off ball, he dribbles into traps, and often pushes his man to the middle instead of to the baseline. Rookie mistakes, but shooting isn't his only problem. In 4-5 years he will be a Rondo clone, which is awesome.