The most important feature I like about CE in general are its many builtin connector types (eMail/Calendar etc). It's also very well documented with lots of tutorials online around it - which can be quite helpful when you're new at this stuff or if there isn't much documentation out yet. Sometimes my clients have issues connecting their CRM tool directly using OAuth2 so they want me first to test connect those tools via another way e.g.: Salesforce Connector; then after everything works as expected we use an additional plugin called "Connectors" from cloud elements where i'm able just point & click without having them set up any credentials themselves by hand!