Hey @dimaip,
I believe we could write the Neos backend with both Ember 2.x and React; both would certainly be doable – and I’d even expect the code to look somehow similar, as Ember 2 (same as e.g. Angular 2) has been heavily inspired by data-down-actions-up of React.
However, when we have migrated to Ember 2 and Ember CLI (which is some route to go still), I see most benefits because Ember 2 has strong conventions (the way Flow has strong conventions as well); and React e.g. does not tell you which file-structure you should use for writing your modules…
I feel that this discussion in the end it boils down to a “library” (=react) or “framework” (=ember) approach.
To me personally, Dries from Drupal has summed up the state of the discussion really well: http://buytaert.net/selecting-a-client-side-framework-for-drupal
However, I’d suggest to move this discussion (e.g. which FE framework to use) out of this thread… And rather focus on our goals and not so-much on how we want to archive them.
All the best,
Sebastian