Final smashes do seem a bit unneccesary. Some are shitty, like Lucarios, but some will end a 5-stock game in the time it takes to finish, such as Snakes. However, the story mode was leaps and bounds greater than Melees, mostly because this one has a story. A silly one, but a story.
The story mode is fun up until you've beaten it once. I've tried a second playthrough, I only got halfway before getting bored.
Melee's adventure is more memorable, slicing up goombas and beating up redeads. I really think the story mode in Brawl should have focused more on paying tribute to franchises like the previous did, I'm sure they could have thought up many ways to expand on it considering how many more different characters they brought in.
I enjoy Brawl, and it's the one in the series my friend prefers playing, but considering the problems and the design flaws it has in comparison to Melee, I'd have to say Melee is probably the better title. And this isn't bringing Brawl's extra "features" into the equation either. Online mode is a complete fucking joke, I can tell you that right off the bat.