He is definitely overrated.
His defense is below average and his scoring is elite while his rebounding is above average.
Not a franchise changing player but a solid All Star.
Put it this way, if he were still in the Western conference he probably wouldn't make the starting five for the All Star game.
He's almost like a poor mans Kevin Durant- where Durant's total domination on the offensive end makes up for his average defensive impact.
The great ones of our recent era like MJ, Bryant, Lebron, KG all dominate on both ends of the floor and that's what sets them apart.
Carmelo also has obvious issues with his weight. Someone who wants to be the best doesn't eat pizza every night like this guy. (I don't know that he does but he certainly isn't making an effort to lose weight).