Sure there are commercial options available, but it is really nice to have some good free or open source tools for a database.
Other than that PostgreSQL looks like a nice database, but I didn't find the "killer" argument to change to it. All the nice SQL syntax changes don't mean too much to me, because I am mostly using an ORM to access the database.
Another thing which isn't working as well on PostgreSQL is master - master clustering. All the solutions I found for PostgreSQL looked inferior to Galera (which has its own pitfalls). On the other hand I think it is far better to have one / two beefy servers than having a cluster of master databases.