The video below shows the transfer of three files (10MB, 50MB, and 100MB) from a local wired server over Wi-Fi.
The iPhone 5 with its 5Ghz 802.11n support clearly blows away the iPhone 4S by transferring at over double the speed. If you previously tried iTunes Wi-Fi sync but thought it was too slow, you might want to give it another try.
The 2.4GHz band is far more congested and thus prone to interference resulting in slower speeds. While the 5GHz band is less congested and can offer faster throughput, its disadvantage is shorter range and difficulty penetrating solid objects.
Take a look at the video below...