actually, you'll get similar performance with 7970 as with v4900, because(among drivers optimization, which does good job in Direct 3D applications) it uses its full power in Open-GL, and CADs and Maya from Autodesk use Open GL, not Direct 3D(in which you would benefit from gaming one). (Open-GL test, it's nVidia, but it's gaming vs pro card and that doesn't matters
http://v.youku.com/v_show/id_XMjc5ODM1NjUy.html )
you'll see many crashes per day with gaming card, when with workstation cards you should see 0, if you'll see contact with support. at least with nVidia is so.
you'll also see real support from all of them - Hardware and software maker who's you'll use(because with them you should not see any crashes, and if you'll see they should take care)
However, if you're doing GPU rendering which use Cuda cores, buy some quadro, if this is the case, and not stability or good support you want, buy high-end nvidia gaming card, you'll see fewer errors with new released gaming cards than from older one.
And, because of this, you can buy workstation card now and use it for years and should see very few(if any) application errors in whole use time. plus is, you can play modern games from Linux