700 allows you to connect to you phone via Bluetooth as well. I love this feature as I can be connected to the xbox in a game and in party chat and if my phone rings, I can take the call. It lowers the in game volume, mutes the mic to the game chat, as it switches over to the phone conversation. As soon as I end the call, the game volume resumes to level and moves mic back to my party chat seamlessly. Well worth the extra money if you see yourself in that scenario.