Is there any recommendable modern CMS (-engine) for Ruby on Rails?
It should not be some 'external' or API-CMS like Contentful but rather something that's fully integrated but still has a modern backend.
It seems that Alchemy CMS, Spina, Camaleon, Fae CMS, Publify, Locomotive CMS (is it worth to have MongoDB as a dependency?), Comfortable Mexican Sofa and Casein are actively developed at the moment. But are they good? I didn't try any of them.
I also found pavecms.com which seems to have a WYSIWYG backend but the company wasn't responsive via the contact form and I didn't find anything about licensing/pricing anyway.
Does anyone has experience and advice?
What are good factors to watch out when looking for a CMS engine?