I mean this in the most respectful way possible, but, your concrete flaws are that you believe it's just designed for the sake of change, it animates too much, and that a font is too small in one place?
For what it's worth, the underlying usability really is very well explained and pretty sound in the material (no pun intended) from Google on MD. Eg: http://www.google.com/design/ in the top 2 items.
In general I feel like surrounded by the Microsoft paper clip. There is constantly something animating, popping up or popping with strong colors into your eyes.
Try to find in all the talk about material design the underlying reasons for usability. There aren't any. To me it feels like the emperor's new cloths.
I was about to buy a Nexus 6 but the new Gmail app is a no go for me and I will avoid it as long as possible.