I am sure the element specs for CVP 8.0 which describe the Web Service Element are applicable to 7.x. Cisco had not updated that document since 2008 and then it was an Audium document with no Cisco changes. So I think that what you read here about the three "technologies" it can talk to is accurate.
There is probably more discussion on the use of this element at the CVP Developer's forum.
I've always rolled my own with Web service calls - using Apache HTTP Client as the transport and JAXB for the parsing and marshaling, but this is because I tackled this problem at CVP 3.0, when there was no Web service element. So I developed an architecture and stayed with it. But I would like to explore the built-in WS element.
Some samples would be good.
Regards,
Geoff