And not the Wii Remote by itself?
For every Wii game I played prior to Brawl, by the way, I'd use the Wii Remote or the Nunchuk scheme, with motion controls if applicable. I got used to it in about a day. The only big things to get used to were Shake Smash and that the jump button was on the Nunchuk; everything else, I customized to how I like it.
(For the record my scheme is as such: On the Nunchuk, control stick is move, C is jump, and Z is shield. On the Wii Remote, A is normal attack, B (the trigger button) is special attack, all four D-Pad buttons are grab, + is pause, - is unused, 1 is up-taunt, 2 is down-taunt, and 1 and 2 together are forwards taunt. With Shake Smash on and me having been very used to motion controls, I could do anything with the Nunchuk scheme that the Gamecube scheme could. After about a week or so, I became more relaxed with this scheme and no longer had to keep my left and right hands together when playing.
Supposedly, there is some kind of small button lag caused by the Nunchuk scheme being wireless, but I've never felt it and never even knew about it until I saw the EVO rules.
What is the difference between Gamecube controllers and Wii U Pro controllers? Isn't the Wii U Pro controller supposed to imitate a Gamecube controller? As far as I've experienced they seem to be about the same to me, though the Wii U Pro controller is somewhat heavier.
By the way, one more anecdote: At Comic-Con 2014, they had a Mario Kart 8 tournament in the Nintendo room. Of the 64 entrants, I was the only one to actively seek out the Wii U GamePad, as it was the only one with motion control steering. Everyone else used a Wii U Pro controller. In other words, I was the lone motion steering player in the group of 64. I won the whole thing.