Currently, in the shell if you created an admin user you need to login to the admin database first and then change databases.

For example, this fails for an admin account:

mongo -u test -p test localhost:27017/test

This succeeds for an admin account:

mongo -u test -p test localhost:27017/admin

MySQL will let you connect to any database from the shell (with auth). This becomes an issue when you'are executing scripts from the shell. Currently, you have to login to admin and then issue a change database.

This will/is confusing for users.