Yes, use it with Atlas for every one of my companies' projects.
- The document model is a no-brainer when working with JS on the front-end. I have JSON from the client, and Dictionaries on the backend (Flask), so it's as easy as dumping into the DB via the pymongo driver. No object relational mapping.
- Can scale up/down physical hardware as needed so we only pay for what we use
- Sharding is painfully easily, with one click
- Support has been incredible