The following LINQ Expression:

...Where(d => !d.BoolField)

Translates to {BoolField : {$ne : true.}} Well, this is not great for performance and the expression is not able to use an index as well as

would be able to use the index.

Since in the driver serialization, we know that the field will always be serialized to bool, it would be better to translate the expression to

instead.

(Note that (d => d.BoolField == false) appears to translate correctly.)