There are a few key differences, apart from the soundtrack and a few general bug fixes and features. The online mode has been greatly improved. The graphics have been given a massive step-up and there are a lot more aspects to the general environment. There are a few more items and some more content, especially in the multiplayer realm. There is also first person mode, which is huge. I don't regret buying GTA V again for my One after having it for my old 360, its definitely an entirely different experience.