I like both styles, the best way is to mix them. Sometimes choreography is a good thing to do, it helps to automate the moves and keeps your brain alert when there are many moves to learn. But classic mitt work is even more important as Tony explained in the video.
I agree. That Mayweather mitt work looks useless. Literally the mitt guy is swinging at the gloves of the boxer.
That's the best way to train novices. Gives them the feeling they are really smashing it and builds their confidence.