sorry for late response.
Let me recap what wise does during ws call. It generate client stub object using standard jaxws tools and then use it (by reflection at the moment, with more efficient javassist in next future) to call the ws. The response of the webservice call will be received as a jaxws generated object and put as is is (if you don't use smooks transformation) in message body default location.
In this description you would probably already get answer to your question about smooks transformation: you would not need transformation if ws returns a "primitive" value (or wrapping object of course). If ws return a more complex object a transformation to objects of your own model would be needed since jaxws generated object are loaded runtime and would be accessed only by reflection.
I know sometimes use of smooks for simple transformaton looks excessive, and I'm evaluating these days some different transformation mainly for similar in/out object model.
Suggestions and requests here would be very appreciated.
I have committed in my workspace some refinement about objects put on message map. Maybe something would be useful for you. They are all on jira under webservice component, assigned to me and even they are in status "in progress" are all done and committed on my workspace.
About samples: wise 2 use a smooks transformation on response, while wise 1 use put directly response on body without any mapping.
Feel free to get back to me if you need some more explaination or example.