I've been experimenting with Netlify CMS too, as a friendly front-end for a few websites/blogs maintained by my less technical friends. It seems to fit my use case very nicely, and doesn't prevent me (or others comfortable with git) making changes without it.
FYI, I'm using it with Hugo as a static site generator, triggered through a webhook from Github, and deploying to my own VM in Azure, which works well. I also chose not to trust Netlify with my Github client secret so I'm running this slightly modified oauth backend on my VM to handle authorisation, and the webhook callback.
I'm not sure Netlify ever intended to compete with the likes of Contentful, they get paid from their hosting, but they were nice enough to open source the thing, so we can all make it better :)
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