On paper it's incrementally better--significantly higher clocks, more RAM and much more memory bandwidth. But the bigger news is that all existing Xbox One games get 16x anisotropic filtering, framerate boosts, v-sync, and resolution bumps (if the game supports dynamic resolution). Not to mention system-wide downsampling for 1080p TV's.

Should be a pretty big bump in image quality for Xbox One games. They demoed Forza running at 4k/60 FPS with PC Ultra-equivalent settings at less than 90% GPU load.