From the look of the trailer it looks like the moves are fast and it doesn't waste your time. I think they learned their lesson with the 4th generation and its slowness. A health bar shouldn't go down slower because you have more hp.
I wish Blastoise was my dad. He wouldn't beat my mom like what her boyfriend, Johnny does. If Blastoise was my dad things would be different around here.
I don't think they will be that bad. I mean, the seem to be having flashier animations for entering battles and attacking, but if they keep the option to turn that off then you can at least speed things up if you don't care for the animations.
However, I can't imagine triple battles NOT experiencing a massive slowdown.