If you're using that kind of schema you won't be getting any of Postgres' advantages. Obviously it has a pretty good reliability reputation, but I'd be very cautious about switching to Postgres because you're going to be making a lot of work for yourself.
If you're worried about performance, benchmark it (or find someone who has). On the reliability side there are plenty of NoSQL options with better reputations than MongoDB. My first thought is neo4j, but I don't really know enough about your particular problem.
If you're worried about performance, benchmark it (or find someone who has). On the reliability side there are plenty of NoSQL options with better reputations than MongoDB. My first thought is neo4j, but I don't really know enough about your particular problem.