There is a whole new approach that you may want to consider if what you're after is the power and performance of stored procedures, and the rapid development that tools like Entity Framework provide.
I've taken SQL+ for a test drive on a small project, and it is really something special. You basically add what amounts to comments to your SQL routines, and those comments provide instructions to a code generator, which then builds a really nice object oriented class library based on the actual SQL routine. Kind of like entity framework in reverse.
Input parameters become part of an input object, output parameters and result sets become part of an output object, and a service component provides the method calls.
If you want to use stored procedures, but still want rapid development, you might want to have a look at this stuff.