Brazilian Mario? Quite possibly one of the worst descriptions I've ever seen on this forum. Neymar runs all day, never gets in trouble off the pitch, and actually delivers on it. He's not known for sulking and doesn't get in fights with his teammates. He's quite clearly delivering on all his potential.
What exactly has he got in common with Balotelli?
Put Aguero in Barca or Real and he'll be getting assists from Messi and Neymar, not Jesus Navas and Sterling. That's why he'd score more goals. Ronaldo scored 31 premier league goals at 22, last season he scored...34. What a difference those easy games against awful Spanish teams made!
I remember how people said Neymar would be awful in Europe, could only hack it in Brazil.
Then they said he'd crumble at the world cup when it mattered, and he carried Brazil to the semi-finals.
Neymar would be the best player in the league if he joined. He goes down too easily, so some people will always dislike him, but questioning his quality at this point is embarrassing.