AFAIK, even the Geforce3 cards are not being used to their fullest potential..
When programmed, a game must use the functions a card has to offer either by DX or OpenGL (whatever) , and I don't think that the matrox cards extra vertex shaders/pixel shaders/texture shaders are used..
I'm not saying that the review(er) is bad, the geforce4 should also be able to perform better when it's features are used to it's fullest, but I do wonder if the extra stuff on the parhelia were used..
Let's wait untill games are programmed using the DX9 API or something similar..