Something that Polymer and Material (IIRC) get right is that when you click multiple times on buttons, new ripples are created each time. In Propeller, the old ripple just "vanishes" and a new ripple is created.<p>I don't know, I've been obsessed with detail of this sort for a while now. I wound up paying attention to things like this since I tried re-creating material design components in pure WebGL, It's stagnated now though: <a href="http://bollu.github.io/webgl-design/bin/paper-material.html" rel="nofollow">http://bollu.github.io/webgl-design/bin/paper-material.html</a>
I'm not sure what the point of this is, Material Design is built on solid design principles which create well spaced and easy to understand interfaces, none of which are goals of Bootstrap.<p>Combining Bootstrap with Material is like putting salt in coffee, and hiding with some sort of identity crisis. You've named expansion panels; accordions, which sure, they do follow a similar pattern, but which library are you basing the naming on?<p>As a front-end developer and designer, this makes me cringe.