Every chance I get, I advocate ArangoDB. It also is Mongo Done Right. You get joins, graphs and a thoughtful future plan from ArangoDB team. To help bridge the gap I've written an ArangoDB Hadoop connector [1]. Unlike the MongoDB one, you can read and write.
I've also added better Clojure support to it: from a driver to a Ragtime migrator.
Sadly as it stands Mongo has a better Ops story than ArangoDB. Until that improves, I don't think that ArangoDB will make it into many Fortune 1000's outside of some small prototype style applications. Maybe micro-services in the enterprise will change this, but I don't think a large insurance company wants to support multiple database standards in general, and definitely not within a family.