Actually, you should think about few things:
1)How important is stability;
2)How important is Cuda cores(GPU rendering and adobe products use Cudas from nVidia, not AMD's);
3)Which one do your apps use - Open GL or Direct3D (DirectX)
1)If for you important is stability, buy Workstation card, I suggest you to buy from nVidia(as they're known to have good stability).
2)If important is Cuda to be in, (where few means bad and many means better, because CPU can handle better than few Cudas on adobe products, in GPU rendering just fast GPU will act as one big Cuda, similar to big single-core CPU vs small multicore CPU), buy new gaming card from nVidia
3)If your apps are Open-GL buy workstation card. Because it really uses it's full power in Open GL(gaming cards have blocked it, as it's not used in games). And, CAD apps and Maya from Autodesk use Open-GL, not Direct 3d. you can search on youtube "quadro 600(or 400, don't really remember) vs gtx"
Plus, workstation cards have hyper optimized drivers for autodesk applications(e.g. Autodesk Maya performance driver), which gives up to twice perf. improvement in maya for this example over basic quadro/firepro driver(which on its side is already optimized).
Pluses for nVidia cards are: they have little bit better support and better drivers.
Pluses for AMD cards are: they have better overall performance than similar priced nVidia card, Firepro v4900 (same class as Quadro 600 and fx 580) supports 3 monitors.
Minuses for nVidia: they are outdated and are an series older than AMD's current serries(those were made against v*800, and amd has released next series - v*900)
Minuses for AMD: they unfortunately eat more power and have some artifacts (as I have seen non-GPU related videos capturing screen on Firepro card, some parts of screen were not refreshing for few seconds until user rotated viewport camera in 3ds max, e.g. some part of dialog box or previously used modifier. that was driver issue and I guess that was fixed since it, as similar thing was noted in autodesk certified hardware list).
If you want to buy entry-level workstation card from nVidia buy Quadro 600 (not fx 580), it's newer, better and cheaper than fx 580.
If you want to buy entry-level workstation card from AMD buy firepro v4900(costs same as quadro fx 580, is 3 series newer, has much better performance).
So, I suggest you to buy v4900 if you don't want Cuda cores for Adobe softwares and sell it when next series similar class card will be available. or if you want Cudas, buy GeForce card which has more than 96 cores(you'll not see performance improvement with less than hundred cores).
Quite long post, however