Mary Lou does it again. Consistently putting out quality work in an easy to understand manner.
I love these Codrops experiments. They're great for inspiration.
In this case though, very few of them (if any) actually increase usability? The transitions seem a little sluggish and I'd like some indication of the contents of the next pane without having to hover the arrow.
It would be tough to prove, but I thing the last example "Fill Path" is a pretty obvious derivative of the "Flexing Pagination" experiment by Hakim El Hattab.
He'd never ask for recognition or attribution, but I'm happy to give it to him. http://lab.hakim.se/flexing-pagination/
Love the Circle Pop animation, not sure about the rest, I'd probably manage to click and transition to the next slide before the hover finishes animating.