Hi - we don't use Advantage, but we do have a totally separate financial tool that we do invoicing, bill rates, expenses, and timesheets in. (Especially since we have a 15-tier rate card process and there is just no way to rebulid that in Workfront)
Because of that, we have a SQL server that we bring in data from WF and the financial tool and then use SQL Reporting Services to create reports to track burn rate, utilization, billable/non-billable, etc. Now that we have the large data warehouse with tons of info, it is great. But it has taken us awhile to get here because I've needed to beg and bribe developers to help me internally. ;)