Having a central place to easily search the backend of Salesforce and see all dependencies. Sometimes the search in SFDC does not work well and does not show what you are looking for, but Sonar you are able to easily search all relevant objects/fields/ etc.

Great place to look at all changes and references in one place.

Sonar is fast and provides needed information fast. It enables one to trace out logic and see connections between parts of one's Salesforce customizations. It enables us to organize work and functionality by tagging design elements in a flexible way. I have confidence in the stability and ability of the team that is still developing this fairly new product. A year later - many new functionalities came out this year and certain flaws were fixed. Useful for admins and developers in the Salesforce world.