You'll notice the difference while loading webpages as its a case of blink and you miss it. Overclocking to 1.6ghz does use a little more battery but not that much more. I used performance governor for the benchmark which isn't supposed to be for everyday use as it drains the battery. I think its more for using when your phone on charge. But still overclocking and using a sensible governor will still make your phone feel a bit speedier.