It's all about the jokes he makes. Jordan's Mat jokes are short and pithy in a stupid kind of way while the jokes Sanderson gives Mat are much more convoluted and protracted and much drier.

I think it's more than that, but that is part of it for sure.

I honestly feel like Sanderson did not really understand the depth that the character actually had before he started writing. I guess it's unrealistic to ask for Sanderson to understand each character like RJ understood them though.

Read Books 9-11 then read Sanderson's version of mat... Not the same character.

He's changed because he's had to mature and take on more responsibility - similar to Perrin, but he was far less of a b!tch about it - I wouldn't say it's due to Brandon, and wouldn't say it's for the worse either - though doing a re-read now I'm enjoying the old Mat a lot :)

How the hell would you consider Mat "more mature" in the books by Brandon? Mat is portrayed as his old care-free childish self. I've re-read the entire series every year on audio books for the last 5 years, and it is absolutely obvious that Mat is actually LESS mature than he was at the time RJ died.

PROOF: When he's testing the cannons... WTF? How the hell are we supposed to believe Mat would ever put himself in a position where he could have gotten hurt? Mat NEVER willingly puts himself in danger like that unless he is bound by his semi-twisted sense of honor.

The current mat appears (at his core) ignorant, childish, and somewhat annoying. A far cry from his personality as portrayed by RJ.

Before I go into detail explaining how Mat's personality has changed (for the worse) due to Mr. Sanderson's perspective of the character... Does anyone else agree with me? If nobody else cares, I won't go into details.