I've just installed a GeForce 7300 GT XFX PCIe 256 MB Card on my Hack. Much to my surprise OpenGL is running much slower on the new GeForce card than when running GMA900? Xbench ScreenShots attached. The nVidia XFX Card is using Omni's Titan and 10.4.8 GeForce Drivers and 10.4.8's OpenGL Framework. Both configs have QE/CI/OpenGL. The only other thing that I know if different is I am using Beta 8 on the XFX Config and was using the Beta 1 on the GMA900 config. I might try the older kernel on the XFX to see if it is any different.
Even though the XBench says even my 2D Graphics are slower with the nVidia card. 2D Window redrawing is more responsive on the GeForce card than GMA900. However, 3D OpenGL graphics is noticably slower with Flurry.