I'm getting stuttering/lag on my Mac Pro when using Mission Control and I believe it's due to the video card as the rest of the system is pretty solid. To my surprise, the Mac version of popular video cards are pretty pricey but I dont want to go through flashing a PC version, so I'm going to buy the Mac version. Looks like the choices I've found online are the Radeon 5770 for $210 or the Radeon 7950 for $418. Is the 7950 worth the extra $200+? Computer is strictly used for graphic design (Photoshop, QuarkXpress, Illustrator).