The description for the 4 different editions of Test Studio (Ultimate, Functional, Load, Runtime) is split between two completely different locations:
http://docs.telerik.com/teststudio/user-guide/overview/test-studio-vs-run-time.aspx
http://docs.telerik.com/teststudio/user-guide/overview.aspx

These should somehow be merged so that customers can all the differences listed all at once in one location.