I am dumb. Why do we want a GameCube controller with this game? Isn't the new wireless pro controller for the Wii U a whole lot better?
A pro controller will cost you $30-$50. A gamecube controller in this bundle is essentially free (if you have GCU). If you already have one or the other, you dont need to consider the bundle. I think it's just a preference thing. If you've been playing since Melee, then you're used to the layout of the GC controller. I found this on wiiuforums.com ...
"1. Input time. The bluetooth connection made with a Pro controller (or even GC wavebird) can have an input lag time of around 5-30ms. Now, that's a very low number, but for competitive players, it can be the difference between that perfectly timed shdl or getting those long landing cooldown frames. If you plug a gamecube controller in, the input goes directly to the console faster.
2. GC controllers have analog triggers, and are generally better for pressure sensitivity. The buttons are better made imo and snap back better, making core gameplay like short hopping easier.
3. Button placement is, arguably, well made for smash bros. The large A button, small B slightly off of it, and Y and X also more easily accessible. For example, if you were playing as Peach and you wanted to combo someone while floating, you'd have to hold Y or X while still being able to use your thumb on the A button. The gamecube controller makes that easy."
Hope that helps.