Yes, we have used SSRS web services before. Although we were unable to import them directly to the modeller.
Instead, we wrote a Java action to perform the call(s) to SSRS and then passed the parameters through to this from the various Microflows - the Java then manipulated the response to generate and display the reports (in our case these were returned from SSRS and displayed as PDF files).
What exactly is going wrong with the import?
I've never used SQL Server Reporting but it seems according to Accessing the SOAP API that it generates a normal wsdl to load in. Might your server run on https, preventing the Modeler from reaching the wsdl? Or do you get an error when importing it?