Well, unfortunately I do not have any meaningful experience in the area, but from what I have seen, if you are doing moderate to heavy workstation apps the workstation card is worth the cost.
Here is a comparison between a FX4800 and a GTX280 (about same in terms of hardware):http://www.tomshardware.com/reviews/quadro-fx-4800,2258-10.html?xtmc=gaming_vs_workstation&xtcr=3
Now, your question does not compare two cards of equal hardware (they are even different brand!) so I don't know how exactly it will turn out. All I can really say is that great gaming doesn't necessarily mean decent workstation. If you are working with small or simple models either would be fine. For extremely complex models, the best workstation card you can afford may be the best bet.