Always persisting object graphs using the embedded document strategy may not be such a good idea even if it sounds like a good strategy which even works well with MongoDB advanced filtering capabilities:
NoRM makes persisting POCOs to a MongoDB collection simple. Object graphs are automatically serialized to a BSON document.
This blog is called myNoSQL and it is written by me, Alex Popescu, a software architect with a passion for open source and communities.
It records my readings, learnings, and opinions on NoSQL databases, polyglot persistence, and distributed systems -- subjects that I'm passionate about.
The opinions expressed here are my own, and no other party necessarily agrees with them.
If you feel I'm biased, I probably am.