Apple didn't provide a full rundown of the features that will be left off older devices, but, as noted in Craig Federighi's quote, "expressive voices and more advanced dictation" are part of the on-device functionality limited to new devices. The company demonstrated the expressive voices feature during its keynote; essentially, it lets you fine-tune how Siri sounds. You can adjust the pitch and speed at which the personal assistant speaks. While it sounds useful, it's hardly a game-changer. The more advanced dictation wasn't dove into as deeply, but Apple did say that it "now captures what us