In my nearly nine years of working with ServiceNow the one request I've heard the most is the ability to report on catalog variable values. There were some ugly solutions that could get you by but Fuji introduces an easier way.
While it's still a bit confusing at first, you should be able to get closer to solving the scenarios that are most commonly requested.
You can filter requested item lists or create reports filtered on a particular item variable. I think the biggest value is when you leverage variable sets. Reporting on variables in variables sets allows you to gather common requests across all of the items using that variable set. You might want to consider this when designing catalog items as this could add value to your application.
Take for example having multiple service catalog items to request various types of server provisioning. If all of the items share a variable set that contains a variable for the operating system, you'll now be able to filter and report on OS values across all of the items.
To follow up on the previous post, this is also another great use case for leveraging report sources since that filter be get confusing to some.