@Bijo

BKS nailed it on the head. Shader Models aren't measured in speed but rather all the fancy shading effects and whatnot they can do. Ahh I can't wait for the day when I can afford a 8800.

Here is some screenshots with FPS in the corner to show you the difference in quality and in FPS between shader model 2 and 3. Scroll down to the middle of the page.
http://www.tweakguides.com/COJ_5.html

As mentioned earlier, the 8800 will blow away a 7900 anyday for just about the same price. Always make sure to research the latest and greatest and then compare prices to an older series/model and then check the price vs performance to see if it is worth the extra $$ to get the latest and greatest. Anymore it seems that if you can afford the extra $50 or whatever it maybe it is a huge difference in performance for just $50. Obviously there are lots of variables, but for the sake of argument, this is mostly true, albeit, after a few months and the initial prices have lowered.