Setting up calendar events proved to be a strong point for Siri, but that's one of the easiest tasks to perform using the Calendar app, with just a few pokes at the 4S' touchscreen.
Ultimately Siri impressed us too rarely, and we don't think its voice-recognition tech is accurate, reliable or useful enough to make it preferable to just opening other apps and sorting stuff out yourself. This is a shame, as we had high hopes for a voice-recognition tool that would blow every previous failed attempt out of the water.
So Siri isn't great, but the voice recognition tech on board the 4S comes into its own in other areas -- you can dictate text messages or notes, and unlike Siri, we can see this actually making your life easier.
Performance benchmark test
The iPhone 4S packs a superior processor to the iPhone 4 in the shape of an A5 chip. Anecdotally it feels extremely slick, with apps opening quickly, menus sliding smoothly and rapid-fire typing proving snappy and responsive. Forget anecdotes though, let's get.
While speedy, the 4S wasn't quite as fast as an iPad 2 running iOS 5, which scored a slightly more impressive 1,805.9.
We also ran a graphics test in the form of GLBenchmark 2.1, an app that runs a videogame-style 3D scenario and ranks the device's polygon-chucking ability. Here the iPhone 4S scored an impressive 6,568, handling the graphically intensive scenario with aplomb, and trouncing our iPhone 4's score of 1,621 (higher is better here).
So the iPhone 4S does deliver when it comes to speed, walloping its predecessor in terms of performance, and proving itself capable of handling some adventurous gaming. We can't wait to see new, ambitious apps that take advantage of this new processor.
The iPhone 4S packs a new 8-megapixel camera that's loaded with optic tech, including face-detection, backside illumination (chortle) and a new sensor. But does that fancy tech translate into decent snaps?
The answer is yes. The iPhone 4's 5-megapixel camera was one of the best in the business, and the 4S improves on that performance. We were really impressed with the dynamic range, with colours looking more natural and balanced than they do when taking photos with the iPhone 4.
There's the option to take some beautiful macro shots, thanks to the depth of field that this tiny snapper manages, while the 1080p video is crisp and colourful. We noticed a spot of rolling shutter making our video appear ever so slightly wobbly, but all things considered, the video capture on offer here is very impressive too.
The software is low on options, but blissfully simple to use, and the snappy processor comes into its own when taking photos -- you'll be able to snap photo after photo in rapid succession, and start recording movies rapidly without the 4S breaking a sweat.
Some killer camera tech combined with simple software and powerful hardware means this is the best smart phone camera we've ever used, and a compelling reason to upgrade to the 4S -- certainly more so than Siri. Look out for detailed comparisons with other leading camera phones over the next few days.
The iPhone 4S shoots video in 1080p, which is a step-up from the iPhone 4, which managed 720p video. We've embedded a short test video clip here so you can see how the iPhone 4S fares for yourself, but in our opinion, the footage this phone captures is very impressive.
There's a hint of rolling shutter, which is the effect that makes your video look wobbly when the camera moves. It's something we noticed on the iPhone 4 as well, and it's not too bad here. All things considered we think this could easily fill in for a proper camcorder when you go on holiday. Apple'sapp (sold seperately, £2.99) serves as a great little video editor too, bolstering the 4S' camcorder chops.
Anyone who's held an iPhone 4 will be au fait with the iPhone 4S' design, because it looks almost exactly the same as its predecessor. While it makes the iPhone 4 and the 4S hard to tell apart, the lack of a new look is not necessarily a bad thing, because this classy slab of gadgetry is still one of the best-looking phones in the business.
A slab of glass adorns the back of the 4S, while a rounded metal band along the edges lends this phone an industrial, modern look. Once the iPhone's button selection looked sparse -- the big 'home' button bang in the middle, circular volume buttons, a switch to turn the phone to silent and a lock key on the top are still all you get. In the last year rival manufacturers have opted for a similarly minimalist style, so the 4S doesn't look as singular as previous iPhones did at the time.
The volume buttons and mute switch have been altered slightly from the iPhone 4, with all three buttons moved down a few millimetres. As a result it's possible that iPhone 4 cases won't all fit the iPhone 4S, if the case is particularly snug around these keys. Most cases have a gap for all the buttons, so should be fine.
One gripe we'd level at the 4S is that it's very fragile. We've had over a year with the iPhone 4, and in that time we've seen more than our fair share of cracked casings and shattered screens. With the same design, the iPhone 4S will suffer just as much if you knock it off a table or leave it in the hands of a destructive toddler.
In conclusion, it's a shame that your mates and jealous commuters won't be able to tell immediately that you're carrying the latest tech, and the fragile casing could lead to tears, but this is still a deliciously classy phone, and one you should be proud to fill your pockets with.
Even the most sophisticated smart phone isn't much cop if it can't survive without sucking on its charging cable, so how does the 4S fare away from the mains?
With what we'd consider normal-to-heavy usage -- that is, brightness turned to full, intermittent Web browsing over both 3G and Wi-Fi, some time spent downloading and playing games and about 50 minutes of streaming YouTube video -- the 4S' battery ran down to 27 per cent from a full charge after 6 hours and 18 minutes.
We don't expect you'll end up using your 4S that much every day though. Based on our experiences, with moderate use the 4S will likely last you through to the end of the day. If you find the battery is draining too quickly, try turning off services you don't use, and checking which apps are monitoring your location in the settings menu, as this could be guzzling through your reserves.
We tried to burn through the 4S' battery as quickly as we could, by running graphically intensive 3D games Infinity Blade and Real Racing 2. The battery died after a little more than 3 hours, so consider that an approximate minimum life expectancy. We also noticed the 4S got very warm while it was running these games -- a sign that its processor is working hard.
These results are in line with our expectations -- we've yet to see a high-spec smart phone that can last more than a day or two away from the mains. We expect you'll need to charge the iPhone 4S every night to ensure it makes it through a full day, particularly if you're fond of downloading things or playing intensive games.
So far the 4S' battery appears to offer similar survivability to the iPhone 4. Indeed, the battery unit inside the 4S is very similar to that of its predecessor.
When the iPhone 4 was released it blew our socks clean off our feet, and caused rival manufacturers to scrabble frantically back to the drawing board, desperate to conjure up something equally cool and impressive. In short, it was way ahead of the curve.
The iPhone 4S is still ahead of the competition, but the gap has narrowed significantly, with Android and even Windows Phone devices becoming slowly more accessible and stylish.
Taking the wider view of the tech industry, it's unclear whether the iPhone 4S is enough to keep Apple on top for another whole year. But forget navel-gazing -- right now we reckon this is the best smart phone out there.
It's a cracking little gadget and it's loads of fun to use, offering more apps, games and multimedia than you can shake a stick at. It's not nearly as striking as its predecessor was, but if you're on the hunt for a powerful, easy to use mobile, this should be your first choice.