// we improved WF designer performance in .NET 3.5 sp1 , After .NET 3.5 sp1 also, you may see some designer performance problems, you can follow these guide lines to increase WF designer performance Commonly reported issues 1. Time taken to open a workflow document is long. 2. Opening Activity bind dialog is slow….
http://www.pluralsight.com/community/blogs/dbox/archive/2008/09/06/oslo.aspx http://douglaspurdy.com/2008/09/06/what-is-oslo/ http://blogs.msdn.com/shycohen/archive/2008/09/08/oslo-and-models.aspx