Recommendations to others considering Sanity:
Be prepared to do the content design work. Sanity gives you the tools to build efficient, effective, future-friendly content, but you'll only get that if you also do the research and design work to define that for your content and your use case. The Sanity docs provide good guidance to get you started. Review collected by and hosted on G2.com.
What problems is Sanity solving and how is that benefiting you?
Oh, so many!
Content Quality Improvement: I recently helped a client move a crucial subset of their content from ad hoc markdown editing to structured content editing in Sanity. By structuring and providing guidance on what constitutes quality in different parts of the content model, content editors were able to produce higher quality content in less time and with less effort. A structured model helped them focus on communicating their expertise, instead of re-inventing a document structure and style guide every time they opened the editor.
Linked Data Publication: On a separate project, we built linked data (think OpenGraph meta tags and Schema.org) into the editor experience, sometimes without even adding additional fields, and made them available on the front systematically via page templates. Instead of editors needing to remember to fill in meta-tags, it's been built into their workflow for every resource.
Knowledge Graph Integration: For the moment, the most visible use cases for Sanity are for managing content intended for web pages. The Sanity API is good at this, but since it is fully decoupled, it is also capable of a lot more (see note on the "mind shift" above): in this instance, we're using a GROQ query to return a set of content data that we then pipe to an RDF serializer to convert it into semantic web triples. These triples are then sent to a graph database that houses a taxonomy and other content data from the same broad project. By then querying this graph database as the UI is being built, we're able to use Sanity as a content source, and the graph database as a dynamic source of business logic. This allows us to prioritize and recommend content based on context, popularity, and the ever-evolving collection of content in which an individual resource is situated. Also: Sanity's support of webhooks means this process is fully automated: all the content creator has to do is author a new resource and hit "Publish." Review collected by and hosted on G2.com.