Bungie made great games, but did not know how to make a 3D engine runs well, and have a top notch artistic direction. Now it's done, and moreover we can run . I have loved and play Halo reach a lot, but this one clearly stands out in my opinion.
Interface is just simply well designed, modern, fluent...Anyway I really dig Halo 4, with the added dynamic during gunfights, and the fact that the gameplay is always haloish and punish you if you run and gun brainlessly. In terms of design and texturing, this game is by far superior ot Bungie who in some areas it was almost full of lazyness. Framerate drops on Reach, Awfull Textures and colors on some maps, for example textures of the floor on Sword's Base rooms, or the colors of Reflection...Just my two cents...