I dunno, I'd rather use "vanilla" React/Redux/JSX than try and get those tools to fit with custom elements, shadow DOM and the html import/template stuff.

The web components specs look poorly thought out to me. They seem superficially like good ideas, but when you actually bother to build something with them you hit the rough edges and missing pieces. I do not appreciate that Chrome rammed them unilaterally down our throats, or that their Polymer evangelists continue to flog these technologies as though they are somehow an answer to the vast majority of problems web developers face.