I work in composites and we CNC machine all our own tools and tools for our customers, so our environment is all about complex surfaces, and Rhino provides vastly superior handling of these surfaces.

The Solidworks reps keep saying that they've hired guys from Rhino and they'll have amazing surfaces in the next version, but it is been the same story for 3 versions. I still find that when working with customers that use Solidworks, when it comes to a particularly complex surface or blend, they tear their hair out for a few hours, and then send it to me to get it done in 20min, then they approve the shape, and we start cutting the mold or part.

If you need to work with complex surfaces, nothing touches RhinoCAD, and their software is solid and their support is excellent. I also use it at home to model home improvement projects, landscaping etc., and it is great there too. The only situation where it might not be as good as Solidworks could be a big assembly with hundreds of parts and simple surfaces, like engine or a transmission.

On a related note, while RhinoCAD is great, avoid RhinoCAM like the plague. They have a license to the name, but it is not the same company, the same software quality, or the same support. I don't have anything good to say about it.