The ease of use, it's ability to be deployed quickly across many environments with minimal impact - no need for custom code or complex configuration. It can also easily integrate into your existing monitoring stack (e.g., Nagios). I'd like more flexibility in terms of being able to configure rules that don't fit well within their current rule set but are still important from an application perspective. We've used this product at three different companies now so we have some pretty good experiences under our belt! Our teams were previously using JIRA tickets as primary way to track issues/defects which was causing them frustration when they couldn't find what exactly about something bothered users. This has helped us focus much better by creating clear paths between user stories & bugs via issue tracking tools instead of having people create new tasks directly in github repos etc.