After last week's announcement, many analysts and technology bloggers got themselves in a lather about a completely new iPhone with a bigger screen. They were disappointed that this year's model looks exactly the same.
It might look the same but the iPhone 4S is significantly faster than its predecessor, with a new camera and - this year's most attention-grabbing feature - a clever voice control service called Siri. In hindsight, this year's upgrade makes sense: it mirrors the 2009 upgrade from iPhone 3G to iPhone 3GS.
The iPhone 4S has a new antenna design, which Apple says will improve call quality. Some iPhone 4 users had problems with dropped calls and the company hopes this new design will improve things. It's also the only external difference between the two models: the iPhone 4S has extra bands at the top of the phone.
The speed increase isn't immediately obvious. Apple does such a good job of refining the user experience in iOS that it has never felt slow, which makes speed increases harder to detect. Still, applications do open a little quicker and there's a responsiveness to the phone that you notice when you go back to the iPhone 4. Once app developers begin to take advantage of the new A5 processor then we'll really begin to see what this phone can do.
Perhaps most impressive is that the addition of the A5 processor does not seem to have had an impact on battery life. While testing the iPhone 4S over the last week or so, I've found that battery life is about the same as on the iPhone 4. I need to charge the phone every evening but I haven't found myself running out of battery during the course of the day
A little exploring soon reveals that the most obvious speed improvement is with the camera. It is ready to take a picture more quickly, perhaps three to four times faster. The improvement is especially noticeable when you want to shoot video.
Apple has significantly improved the camera in the iPhone 4S. It now has 8-megapixels, rather than five, but the company stresses that the improvements go beyond megapixels and encompass an improved lens, a better sensor and various tweaks to the software. The result is pictures that are sharper, with better colours than before.
The addition of full, 1080p HD video is an added bonus. Videos shot with the 4S look incredible on a big screen. The camera is far better than on the iPhone 4, and a massive leap from the 3GS.
The speed and the camera are all very well but the star of the show is Siri, Apple's "humble personal assistant". Just speak to it and it will answer your questions and carry out tasks. The possibilties are broad and are compatible with apps right across the device. Siri can set alarms and calendar events, send texts and emails, play music, check the weather and search the web.
There is Wolfram Alpha integration, providing answers to all kinds of data-related questions, whether you want to know the height of the Empire State Building or the square root of 512. Siri also takes dictation; any app with a keyboard now has a microphone icon that shows you can dictate your text.
Siri 'hears' very well. After you've spoken to it, the screen displays what Siri thinks you said and, in my testing, the degree of accuracy was very high. Unlike many voice control systems, which require you to learn specific commands, Siri responds to natural speech. There are limits, of course, but Siri understands a surprising amount. Since it's still in beta, you can expect it to improve, too.
There were occasions when Siri got confused, even giving different answers to the same question. For example, the first time I asked Siri "Who is Barack Obama", it returned a page from Wolfram Alpha about the American president. The second time I asked, Siri didn't understand the question. Background noise, as well as the speed and clarity with which you speak, can affect Siri's performance.
The assistant has a gentle sense of humour too, as you'll notice if you start to play around a little. It offered to "write a play in which nothing happens" when I asked it the meaning of life, for example.
Talking to your gadgets feels a little awkward at first. It makes sense in the car, for example, where your hands are busy but how comfortable will you feel chatting to Siri on a crowded train?
For me, Siri is most useful for quickly dictating and sending a text message that would otherwise take a minute or so to tap in on the touchscreen. Britain doesn't yet have Siri's local search features, which allow you to ask for a nearby Italian restaurant, for example, but those are coming.
Apple's critics will tell you that other handsets have had voice control for some time. The iPhone has too, for that matter. But Siri is an important step forward. There were touchscreens before the iPhone came along in 2007 but Apple changed the game. Siri feels like an advance of similar significance.
Overall, the iPhone 4S is a good upgrade to a very good phone. It retains the stylish design of the iPhone 4 and gives it a substantial boost. It's certainly not cheap when you consider some of the alternatives but it feels like a luxury product and it's an absolute joy to use. If you own the iPhone 4, then whether you upgrade or not depends on how tempted you are by Siri and the new camera. The upgrades in iOS 5 might be enough for iPhone 4 owners. 3GS owners should be in the queue already.
Bolt on iOS 5 - the new version of the operating system - and iCloud, Apple's cloud storage service, and you have a pretty compelling package. It's especially compelling for those iPhone 3GS owners whose two-year contracts are just coming to an end
