I hope he stays in Cleveland.
The greats of the great have normally stayed and built championship teams themselves. Maybe he is overrated.
Great like Magic, Michael, Jordan, and Bird all stayed put (until the end of Michael's career, anyway).
Greats like Shaq, Wilt, Kareem, and Oscar Robertson moved on to other places.
I don't think there's necessarily any one mold for a superstar. If Lebron leaves, I don't think it will hurt his legacy unless he can't win a championship in his career.