The OpenStack community uses Gerrit pretty widely across our various projects. It might help to check out a busy project like Nova (https://review.openstack.org/#/q/project:openstack/nova,n,z) to get a feel for how Gerrit works in practice. Or a less-busy project like Bandit, which I'm involved in (https://review.openstack.org/#/q/project:openstack/bandit,n,...).