I recently had a similar dilemma upgrading my gfx card for video editing/compositing and 3D work with Max. I decided to go with the GTX 580 3GB.
Keep in mind that when choosing a card for 3D, you will probably not use more that 1GB of your VRAM in the viewport - the larger amount will only be used for GPU rendering. I'm not certain about Maya but with Max the GPU accelerated render engines are not even used for production.
What it comes down to is this: NVIDIA GTX cards are cheaper and also very powerful. QUADRO cards are designed specifically for 3D and have better cooling, support and drivers that are tailored for design and IMO not worth the $$.
However if you go with a GTX I would choose a better one, like the 570 or 580.
I don't know if you have already bought the card you were after but good luck anyways!