You mean the animations demo? This is to showcase how to work with animations to speed. CSS3 Transitions/Animations have the same performance regardless of the framework.
I think he's just saying you should have used a lower transition time, like 100 or 200ms. It has to do with nothing more than the impression it makes on the user. It's "illogical" but if one of your examples uses a slow CSS transition then the framework "feels" slower, even though the two things have nothing to do with each other.
