Durant is more refined than Lebron was at his age. Lebron is better than he's ever been, he's in his prime, the player he is now is miles ahead of his Cleveland days..........yet Durant, who's 4-5 years younger is maybe a step or two behind him. That's pretty good. It shows when you their first Finals/Playoffs runs.
25ppg (41%fg), 8rebs, 8ast (22 yo Lebron, 2007 Playoffs)
28ppg (51%fg), 8rebs, 4ast (23 yo Durant, 2012 Playoffs)
22ppg (35%fg), 7rebs, 7ast (22 yo Lebron, 2007 Finals)
30ppg (55%fg), 6rebs, 2ast (23 yo Durant, 2012 Finals)
You could make an argument for Durant