GF FX5700 ULTRA OR GF FX5900XT?

[Sakhat]

I found 2 good video cards [Gigabyte GeForce FX 5700 ULTRA Video Card, 128MB DDRII, 128-bit, DVI/TV-Out, 8X AGP] for $179 and [XFX GeForce FX 5900XT Video Card, 128MB DDR, 256-bit, DVI/TV-Out, 8X AGP] for $189. Sure you will say that 5900XT is better that 5700 Ultra. But 5900XT has Clock Speed 390MHz and Memory speed 700MHz, When 5700 Ultra has Clock Speed 475MHz and Memory speed 900MHz.

So which one is better? And is there so big difference in Brands? Like Asus, XFX, eVGA, PNY or they are almost the same? Difference only in $10. I found very cheap Online Shops, One of them - [ NewEgg ]