Once it is released, along with Smash, it'll be a day 1 purchase for me. Ever since my Wii (2009 model) began having difficulties reading my SSBB disc somewhere in 2013, I ended purchasing a Wii U as a replacement in order to continue playing SSBB. Unfortunately, the GC controller that I have long since used and grown accustomed to is no longer an option, so I've settled with the Classic Pro Controller. While a worthy substitute for my GC controller, my experience with it wasn't all that great.
I main Ike and I find it rather annoying that, for any character, whenever I want to use special attacks that involved charging (i.e. Quick Draw) the attacks would often charge partially and then the rest of the animation would proceed by itself despite my finger being held on the button. This is especially fatal in competitive matches; for instance, if I get sent far off-stage as Ike and start charging Quick Draw to recover, there are times when the move doesn't charge as long as I wanted it to and ends up being released on its own. Is this what people call "wireless interference"? The controller is excellent when it works, though the GC controller I still find ideal for a game like Smash Bros.
*sigh* It would be a real joy to experience Smash with the GC controller again.
^-^