My wife and I are sticking with the iPhone 4S rather than buying the new ones (not to mention all the accessories we'd have to replace, from cords to bedside clock/chargers). However, we did download the new iOS7 operating system, which will take some time to get used to, but seems to be worth it.
One of the options is the ability to give Siri a male or female voice. I stuck with the female voice, but my wife switched to the male voice, who quickly became her best friend. Now the four of us are planning to go on a double date -- if we can figure out the "merge your calendars" app.