which video card would you suggest

i just purchased a new dell precision so i can have two video suites in my office and i happen to have two Nvidia 8800 GTX 768MB cards in my old machine that i can use (only one) in this new dell which i bought with a Quadro 1500 256MB. This new system has 4Gb RAM, 2 Quad Core Xeon at 3Ghz, 1333Mhz sb (two of course), and i just want to know if any one knows if it would be worth the time to swap out those cards for the sake of my video production time.