I have found that by using the "Split Line" and breaking up the surfaces into smaller sections I can force SolidWorks to get finer meshing, but perhaps it can work the other way too?
There are other applications that can decimate down to a very low number of polys and still preserve a reasonable likeness of the original.
Meshlab and Blender are a couple of free apps that come to mind. If you have Geomagic or Netfabb, those can do it too.
Both suggestions look very promising (Meshlab and Blender). I installed Meshlab and am running some tests with quad decimation. I'll also look at Blender and let you know how it goes.