Personally I prefer an all JS solution because it's better suited to handle conditions and loops as compared to using custom SGML markup with framework-specific tags and attributes. In my opinion SGML/XML should only be used for markup, not program logic.

There are a few things I think React got wrong though - handling of children being one. Having different code paths to handle a single child versus multiple children was a design mistake. The Children convenience module is awkward to use. The state life cycle and immutability in React takes a while to get used to. It does seem more complicated than it needs to be and has spawned a plethora of React state management add ons.