Craig from Citus here. Thanks for the kind words Justin, as you mention there is some upfront work, but once it's in place it becomes fairly manageable.

We've been working to make that upfront work easier as well with libraries that allow things to be more drop-in (ActiveRecord-multi-tenant: https://github.com/citusdata/activerecord-multi-tenant and Django-multitenant: https://github.com/citusdata/django-multitenant)