WordPress command line is a must-to-have if you are running a WordPress site or multisite.
If you know a bit about crontab and bash scripting, you can easily make an automated job that will upgrade all your plugins and themes on a regular basis.
But be aware, some plugins and themes might break, so you might want to have some testing and checking after an upgrade.
We installed it on our server, and it makes our job much easier:
In order to upgrade all plugins:
wp plugin update-all
Upgrade a specific theme:
wp theme update themename
To get more information about a command:
wp help theme status