Ask HN: WordPress templates using the new REST api

I read recently that WP is moving full speed towards using REST, and people had a few months to take the plugin for a spin. Are there any paid or free themes using it, and what are some opinions from someone that used them in production. Is this ready for prime-time, or should I wait another 6-12 months before considering it? I would like to buy a theme in the near future, and use WP as my CMS for web and mobile, using the REST api.