Mike,
I can relate to the amount of work you will need to expend to finish your modeling project. I have two Solidworks cad models of historic railroad equipment that I have started, but may never finish. Not only are they a lot of work, but also I am discouraged by the graphic feedback.
The graphic result you are obtaining with Carrara is as excellent as I could possibly imagine. It is very easy and natural to look at. The native images in Solidworks, however, are somewhat abstract in terms of lighting and perspective. I don’t know why that has to be. People tell me that it can all be optimized, but nobody can explain how. I read forums where industrial designers talk about rendering in Solidworks, and much of the discussion is truly what could be called rocket science.