I would suspect that you are benefiting from the planned and quite possibly already in place upgrade to the Bungie--->Mobile Devices infrastructure that they will be using for Destiny. Since the game is going to have a lot of notifications to mobile devices, it would make sense (at least to me) that they would be in the process if not completing their upgrades and connectivity to various wireless providers for the mountain of traffic that Destiny is going to generate. Since there currently isn't any Destiny data going out on that connection, Bungie.Net notifications are blazing through because there's not any competing traffic.