What does the Report builder profile permission control? If i have this permission unchecked and the create and customize permission set, i am still able to use the report builder. If i have the Report builder permission set and create and customize unchecked, then its as good as run report, i am not able to customize or create reports.
Just go through these links. Hope this helps.
The Report Builder permission gives the user the ability to "Create, edit, and delete reports through the drag-and-drop report builder interface." This is the newer reporting tool. The separate permission "Create and Customize Reports" is the one that allows the user to work with reports at all.
Here's a list of all permissions available on the profile and in permission sets.