Personally the only way I found Brawl better, was the cutscenes.
Intro, worse.
Menu's, worse.
Graphical style, worse. (preferred the cartoony brightness of Melee to Brawls gritty 'realism')
Levels, worse. (too many 3 platform layouts) Although it did give us the Wind Waker level.
Speed, worse.
Single player mode, worse.
No Break the Targets.
Was disappointed in the new characters and clones.
Though it was packed full of more Nintendo goodness!!
(Although I'd rather the actual game be better and do more justice to the content)