"Better" but not particularly necessary. I've used 3DS Max on various gaming graphics cards with no issues.
Where are the objective benchmarks from you comparing the framerates your are getting with pro cards to the gaming cards??
Would like to see some TBH.
The benchmarks I have seen,indicate that for viewpoint speeds the drivers on the professional cards are much better for viewpoint,and that is what a few people I know who do such work have told me too especially for complex scenes. OTH,gaming cards can overcome the better drivers of the professional cards, in rendering benchmarks due to the much greater grunt they usually have over the similarly priced professional cards.
Edit!!
Another consideration is also image quality,which is usually worse on consumer cards.
Toms Hardware had this comment about it:
http://www.tomshardware.com/reviews/firepro-v3900-review-benchmark,3153-13.html
"Workstation Card or Consumer Card?
We included the V3900’s desktop cousin, the Radeon HD 6570, and Nvidia's entry-level GeForce GT 430, which shares the GF108 chip with its workstation sibling, Quadro 600. Consequently, we see some massive performance dips attributable to the consumer-grade drivers. You're asked to pay a notable premium for workstation cards built on familiar graphics processors and their specially-optimized drivers. But even if that deliberate segmentation seems excessive, for folks whose jobs depend on good performance and validation in money-making applications, paying the extra money is probably justified.
Image quality is something that can't be quantified using the bar graphs from a benchmark. However, the mainstream gaming cards do have noticeably inferior image quality. We ran across plenty of examples of edges that should have been hidden, but weren't (see the picture above), which you simply don't see from workstation cards. The professional hardware also renders wire frame models and textured areas much better. If you use CAD software for a living and want the best results, you really should be using a FirePro or Quadro, and not a Radeon or GeForce. If you're just experimenting with professional software and don't require professional quality, you may get by with a consumer-grade card."
So I suppose,the question is whether you game more or do more 3D stuff??