The difference between His Airness and LeBron James is pretty simple: LeBron James was crowned the Chosen One in middle school, coddled his entire AAU/HS career. LeBron never faced any obstacles that motivated or challenged him to develop that killer instinct. At no point in Jame's career has any friend, teammate, coach or GM told LeBron he wasn't good enough. He was content to ride off his god-given talents.
Michael Jeffrey Jordan, on the other hand, was cut from his varsity team in High School. Someone once told him that he wasn't good enough in basketball. It ticked him off so much, that one defining moment gave born to a unyielding competitive urge to prove everyone wrong. Jordan developed a competitive drive that was unparalleled in the history of sports. That killer instinct was what drove him to outwork everyone of his peers--in the off-season, in practice, on the court. It was what allowed him to go 6 for 6 in the NBA Finals, win 6 Finals MVPs, and average over 30 pts in his playoff career.
Bottom line, LeBron James will never be MJ. LeBron may be bigger, stronger, faster. But the fundamental difference between LeBron and Jordan is and will always be Jordan getting cut in HS, while LeBron got the rockstar treatment.