Buzz-worthy: iPhone 5 cranks up the vibrations
The vibration component in the iPhone 5 is actually an older model, and not the later version found in the iPhone 4S. And that makes for a louder, harsher effect.

Apple's iPhone 5 has stronger, louder vibrations than the iPhone 4S. And that seems to be because of some old technology that's landed in the company's latest handset.
When the iPhone 4 shipped on AT&T's network, the device came with a small vibration motor. However, when the device was offered up to Verizon customers months later, it had a different component that was both larger and more streamlined. The result? Smoother, softer vibrations. That same component came in the iPhone 4S.
But The Next Web, which was first to report on the timeline, says that the iPhone 5 comes with the vibration motor found all the way back in AT&T's iPhone 4. The site discovered Apple's curious move in an iFixit teardown. And as The Next Web notes, iPhone 5 users have noticed that the vibrations coming from the handset appear to be stronger and louder than those in the iPhone 4S.
So, why might Apple have gone back to a previous design? An iFixit screenshot seems to indicate that the older vibration component is much smaller than the latest version. Considering Apple's iPhone 5 is notable thinner than the iPhone 4S, the company might have needed the additional space to accommodate the smaller design.
Of course, that wasn't the only change in the iPhone 5. As IHS iSuppli reported in its recent teardown, Apple has swapped out nearly all of the iPhone's components. The iPhone 5 now comes with a different battery and a swap in DRAM, among many other modifications.