I don't know about the quadro's look up some reviews through google but again it seems as though you just looked at the most expensive one and assumed it was the best
I would think that card would serve him better than the 8800GTX, for what he is doing. Please correct me, if I'm wrong. If I remember, he mentioned using CAD and, he's an architect.
precisely kobe gaming cards are for gaming and that is what they are designed for quick fps whilst cad cards are designed for slower performance because theyre for multi level detailed models
I'm not advising this, but what you could do, since you have the money, is build two separate rigs. One for CAD and designing related stuff. And one for gaming. To test them out?