I like how easy it was to set up this system with my agency's website platform (Wordpress).
It just worked! Nothing really - you can't do much once setup unless there are additional modules available from their site as well which isn't always something we want or need. We use ATS primarily for appointment scheduling but also have some clients who utilize other systems such as Salesforce. This integration has been great because now appointments aren't lost when they're moved between different platforms/systems.