Notice that BOTH GameSpot and IGN gave Panzer Dragoon Orta a perfect grade for graphics (10 and 10). If you actually read the reviews, they both say Panzer Dragoon Orta is the best looking game ever (OXM, GameSpy, and a bunch of others websites/mags say the exact same thing). Panzer Dragoon Orta looks even better than DOAX and Splinter Cell.
Xbox titles just keep getting better and better graphically, and they will continue to do so.