Flexible reporting: easy to create reports that allow you to visualize the data in a number of formats on-the-fly
Data-entry: most reports can easily flip into 'Grid Edit' mode which allows for quick data entry from your view of the data
Application simplicity: it was straightforward to create an application and its underlying data. This required application expertise, but could be done by business users without heavy involvement from IT. This was a big perk for our organization.
Built-in email/alert engine: we used Quickbase to trigger notifications to certain users when data was added, changed, or deleted. This was fantastic to manage workflow.
Quickbase has an API; however it does require expertise to link 3rd party applications via this API. We liked the Quickbase interface so much, we built several integrations to marry the data in the QB platform for analysis.
Most support was handled via online resources. No live support staff was available. This is an area that Intuit could improve. Response was good online, but sometimes it is nice to speak with support staff directly.
I gave it a 10, but it should be a 9.99. They do a nice job of keeping the application running. The application can drag a bit when you have thousands of users accessing the application concurrently. We experienced this with large scale implementations.