As you may already know, you can upload or publish report server content types to a SharePoint library and then view and manage those documents from a SharePoint site. This is after you install the Reporting Services Add-in on Microsoft SharePoint Server and configure for integration.
Carl Rabeler, Senior Program Manager on the SQL Server Customer Advisory Team, explains in his article Reporting Services Performance in SharePoint Integrated Mode in SQL Server 2008 R2 that there are differences in performance between products when you integrate SQL Server and SharePoint Products. The following diagram summarizes the performance improvements between different configurations and products. In short, Reporting Services in SQL Server 2008 R2 and SharePoint 2010 (with Windows Server 2008 R2) delivers significant performance improvements compared with SQL Server 2008 and SharePoint 2007 (with Windows Server 2008) in both native and SharePoint integrated mode.
For more information, you could check out Configuring Reporting Services for SharePoint 2010 Integration.