Hi guys, ReactJS sounds like an awesome choice and you have my +1. Out of curiosity - Angular is not a contender?
Do I understand correctly that essentially for SS4 CMS you are decoupling logic/API and the CMS views? Or would integrating React actually mean a heavy rework of what's out there (note I'm not too familiar with state of progress, but felt this was a conversation I wanted to join in). Doing that kind of decoupling, that would mean that integrating angular or another front-end framework could come out of the box.
If intelligently done, SS could integrate pretty rapidly with frameworks like Polymer or Ionic (on the frontend as well). And maybe even be "themable" in a way that up to now was largely impossible (e.g. Polymer, Bootstrap, Material, Foundation themes for backend being relatively a breeze)
We have recently done multiple sites on Ruby/Angular and I keep missing SS's modular approach to building view elements. Essentially we need to build out all the interfaces by hand and I always dream of an angular version of "new Form()".
To finish this off, I think my mentioning of Angular essentially serves as a +1 for ReactJS. If we could somehow bridge the gap and have whatever JS "MVC" framework is the basis for the CMS to receive schema(mode) / form information from the "SS API", then this would open up very exciting possibilities (and possibly a reactive, non-refreshing CMS interface).
Has anyone seen and worked with Meteor? That thing is reactive out of the box.