Great video. :good Mayweathers routine works for him, but it's not realistic. There's no power, accuracy, fighter that's going to come at you like that, May doesn't have that kind of output, doesn't face fighters who have output like that... It's totally unrealistic. If anything it's just a good way to finish a round off on the pads.
I always thought Mayweather's mitt work was to simulate/prepare him to fight out of that shell defense + shoulder roll stance. I don't think he's practicing 'punching' the pads but parrying them. It's true, he doesn't face a lot of guys with that kind of output anymore (I wonder if that style was developed for him when he was in the lower weights?).