Just upgraded to version 7 and have noticed multiproject reports take nearly 10 minutes to run vs. less than 30 seconds on version 6.
Improvements to software should take us forward not backward.

Newforma’s Support is pursuing this directly with wcallahan.  We’ll update the post when root-cause / solution is identified.

We have identified that the root cause of this issue is a defect in the way Newforma queries project items for reporting.  We are working to address this issue for future releases of 7th Edition.  In the meantime, you can try running multi-project reports on smaller groups of projects, as opposed to all projects at once.