I just recently got the demo of the game from someone in a Nintendo website, even when I'm not a Platinum member of Club Nintendo.
Anyways, few of my thoughts of the demo are:
>The controls are a bit awkward to some first-timers, myself included, though it will take some time get used to it (mind you, this is my second Smash Bros. game)
>Based on my past observations and experiences with Brawl, the game is faster than Brawl but not as fast as Melee, if reports from experts are also taken into account
>I'm liking the buffs some of my mains are having since Brawl (especially Mario, being one of my mains)
Overall, even as a demo, I would definitely say that this game is an improvement over Brawl because I did feel that Brawl is slow and floaty as time goes on when I keep playing with it. But I didn't bother noticing it because I had fun playing with my friends and relatives. I would definitely come to like the full game by the time it is released. Until then, I will keep playing the demo until I have mastery of the controls in a portable Smash game.