So I have mostly used CouchDB over the last few years. I've been really happy with it. I mean, generally the first thing I would have to do if I had a datastor

So I have mostly used CouchDB over the last few years. I've been really happy with it. I mean, generally the first thing I would have to do if I had a datastore is write a REST layer on top of it. With CouchDB, that's just done already. I love that I can just use streams to pipe things around to and from the database. On the simpler apps, I basically just end up writing a small node proxy server that passes HTTP requests to the server, and optionally filter/sanitizes the data on it's way through. I absolutely adore the _changes feed, which allows me to open a socket to it and handle events from the db in "real-time". And the replication is just so simple and powerful too. Now I'll admit that it's views have some real deep problems, but I hardly ever use them except for the simplest of simple things. Mostly when I have any kind of somewhat complex query i need to do, I add elasticsearch with the couchdb river. This listens to the _changes feed and indexes the data. So I query against the ES instance and PUT/GET against the couchdb. I really love those tools, they are so simple and powerful, and hardly give me any real trouble (well, nowadays). Other than being forced to for a job, I can't see why I would use mongo instead of couchdb for anything. But really, this question is mostly about what I should tell my friend.