If you still are not sure you want to upgrade to the iPhone 4S iPhone 5, maybe video from Pocketnow this helps. In this video you can compare the two iPhones in the category: hardware, specs, speed of application, the speed of the web browser, the screen quality, battery life, gaming, and more.
In many respects, it is clear the two devices are very different: the design of the iPhone 5 also feels new, it has a different connector, and includes the hardware has changed dramatically. Thus, the iPhone 5 could be expected to be able to open applications faster than the iPhone 4S. Browsing the web is also a bit faster, better screen quality, photos taken with a better camera, and so on.