There are some glitches when animating layouts. The "primary action button" (is that what the floating circle was called?) sometimes covers the scrollbar after resizing the window, and jumps around on mouse-over; and when the browser window is not maximized, after selecting an option in the left vertical menu, the floating panels jump around a lot vertically before stopping. I'm using latest Chrome on Windows 7.

That's up for debate. I have disabled the animation in L as they were too distracting.. Although I like Material Design overall.