I work with both MSSQL & MongoDB. Please excuse me if I am repeating what was already said above.

My frustration is the same as other DBAs supporting MongoDB. Those that do not understand MongoDB, attempt to use it like a relational database. They are surprised & upset that when I inform them that standard functionality to a relational database, is not available in MongoDB. They some how in there minds think that if the software calls its self a database, that it has a minimal set of functionality (mostly what is common in relational database).

In my experience, MongoDB has worked an excellent document database. Again, it is a document not a relational database.