First of all, the comparison you suggest isn't really valid since SolidWorks is really a parametric solid modeling software package, while The Autodesk Suite encompasses several different software packages, one of which, Inventor, is roughly the functional equivalent to Solidworks.
In an attept to answser your questions:
- The surface modelling functions that Autodesk offers are primarily part of other Autodesk software packages and not Inventor. From my perspective, the choice between one or the other comes down to interoperability with other engineering software like Product Lifecycle Management/Product Data Management tools, how they deal with legacy data and, in many cases, interoperability with the customer's software.
- As others have mentioned, surface modeling is just that, modeling of just the surface. There's no material properties and the models aren't parametrically driven. Their real application is in things where apprearance is the primary goal (think artist's renderings, sales brochures or animation).
I've used both Inventor and Solidworks (along with Catia and Pro/E), though never as part of my primary work function, mostly to revise and modify existing parts. I prefer Autodesk Inventor over Solidworks, but it's really just personal, I know others who feel exactly the opposite.