Can anyone suggest a quality graphics card for viewport display and GPU rendering?

Currently I have a Quadro FX 4600 and I find it to be a waste of good money. I upgraded to Max 2012 and see a great improvement in viewport response, but I know it can be better. Can anyone suggest a card that has good bang for the buck? I have done some research but it leaves me confused.

I have and Asus P6T Deluxe MB on this particular machine…perhaps I can add a 2nd video card rather than replacing the existing? Does that make sense?

Interesting, I’ve been thinking of upgrading my Gtx460 to a Quadro 4000 because of better viewport performance and antialiasing, what makes you feel your Quadro is a waste of money?

Oh, I am not referring to the new Quadro 4000. I am actually considering that one myself. I currently have the Quadro FX 4600 which is a few years old. 2 different animals.

any1 tried the Ati 6990 for viewport performance?

I have a 5870 and am very happy with the viewport performance in terms of fps so the 6990 should be even better, but I think the next level up in quality would be a FirePro or Quadro and not really a faster desktop card. I haven’t worked with these, but I understand they are superior in terms of smoothness and antialising.