Review: iPhone 5 takes next step in smartphone evolution

The iPhone 5 also supports something called "wideband audio," which I suspect is Apple's way of referring to HD voice. It's a technology that expands the range of frequencies transmitted over a voice call, making calls sound richer and more natural. (If you've used Skype or FaceTime, you know very well how poor the plain-old telephone system is when it comes to audio quality.)

This is technology in its infancy, however: Generally, it'll work only when you're communicating with someone who uses the same carrier and who has a phone with the same technology—for example, if two iPhone 5 users connect via Deutsche Telekom in Germany. (There are a few carriers that transmit wideband audio between carriers, Apple says, but not many.) Right now this technology is being used primarily in Europe, though it's slowly making its way around the globe; Sprint has laid some groundwork to support similar features here in the U.S. It's an exciting prospect, improving the quality of voice calls, but I get the sense that it's a few years away from becoming something most people can use.

The iPhone 5 comes with a set of Apple's new EarPods headphones. They sound a lot better to me than the previous default set. For more on that, see R. Matthew Ward's Apple EarPods review.

Similarly, the iPhone 5 is powered by the latest version of Apple's mobile operating system, iOS 6. For much, much more on that, I'll refer you to Dan Moren's comprehensive iOS 6 review.

Bottom line

Robert Cardin

Every time Apple releases a new iPhone, I hear the question: Should someone who has last year's model upgrade? In general, the answer is a qualified no. Apple knows full well that most U.S. iPhone users (and indeed, many overseas as well) buy their phones subsidized by their carrier in exchange for a two-year contract extension. The iPhone 5 is a great upgrade, but should an iPhone 4S user pay a massive penalty to upgrade? Probably not. And that's not the point, anyway. The iPhone 5 is a nice upgrade from the 4S, but it's a massive improvement over the iPhone 4 and 3GS, the models from which most upgraders will be coming.

Does the iPhone 5 live up to expectations? Unless you expected something impossible and miraculous, I think the answer has to be yes. It's by far the fastest iOS device ever in terms of processor and graphics, and its support for LTE networking makes it the fastest iPhone in terms of cellular data transfer speed too. It's so thin and light that it almost (but not quite) taunts the laws of physics. And the black-and-slate model is breathtakingly gorgeous.

Once again, Apple hasn't reinvented the iPhone. All it's done is make the best smartphone around even better.

[Updated 9/28 to remove incorrect mention of antenna configuration and clarify cosmetic aspects of unibody iPhone 5 case.]