Just judging by visual quality, something in between DX9 and DX10. Though the sdk for the consoles may provide something different.
They aren't as good or better than PCs because their hardware was developed during the time of the GeForce 7800 series (I forgot the ATi counterpart). After that time there have been massive leaps on PC hardware (think GeForce 2 series and ATi 4000 series).