Vue uses graphic cards for opengl preview only, not for rendering. For rendering, it only uses CPU (and RAM). So, if you have a very good graphic card, the only difference is that you have a very good and fast preview, nothing else. It's good for precise positioning elements on a scene, for example, but you can have an average graphic card for that, you don't need a high-end one nor a dual one.

I'm not sure about differences between rigs for 3D apps or gaming (I'm not into gaming myself) but I would say they're not similar because games typically use the graphic card intensively, Vue doesn't. I don't know about other differences.