FINALLY! 60FPS! So buttery smooth... I actually was just looking on how to edit and render videos in 60FPS for RU-vid... What editing software do you use? I use Sony Vegas Pro 12.
Luigi is generally a heavier hitter compared to Mario, who is a more well-rounded character (see how when their attacks first hit, Luigi dealt 15% while Mario dealt 12?), besides that, Luigi's side special gives him slightly better recovery compared to Mario, whose recovery is only good vertically.
It's only in project M, which is a modification for brawl. In the mod, there is a special setting called "turbo mode" which allows you to attack immediately after landing a move. This video was recorded in turbo mode, so all they had to do to attack after up b is press any button!