Apple's new iPhone 5s isn't a huge leap forward, but touch ID and a faster processor should keep most users satisfied.
Design & display
The iPhone 5s retains an almost identical physical design to its predecessor. It has a 4-inch screen with 1136x640 resolution.
The screen remains one of the best in the market in terms of clarity, colour and viewing angles. However, its size is tough to swallow if you've used a device like the Samsung Galaxy S4, the HTC One or even Nokia's Lumia 1020.
The iPhone 5s uses the same anodised aluminium finish as its predecessor, but there is two new colours and therefore three colour options in total: gold, silver and "space grey".
The most notable feature of the iPhone 5s is the home button, which doubles as an optical fingerprint scanner.
The touch ID system enables users to unlock the phone without the need for a traditional passcode. It's fairly easy to setup, and works effectively 95 per cent of the time.
Apple's setup process takes a few minutes and even requires users to scan the sides of the finger in order to provide better results. After a few days of using touch ID, it becomes second nature.
Touch ID can also be used in place of an iTunes Store password when purchasing apps and content, and will also work with the App Store and the iBooks Store. However, it does not work with any third party options.
Software & performance
The iPhone 5s obviously comes with the newest version of Apple's mobile operating system, iOS 7. New features include a completely revamped user interface, AirDrop wireless sharing, and an all-new Control Centre.
It has received mixed reviews but it is a significant improvement over iOS 6, which looked dated compared to its Android and Windows Phone competitors.
The control centre, accessible by swiping up from the bottom of the screen, is without a doubt the most useful new feature.
It eliminates the need to delve through the settings menu to access commonly used functions like Bluetooth and Wi-Fi, allows users to quickly adjust the brightness, and has shortcuts for the camera, calculator, timer and flashlight.
Notifications remain significantly inferior to Android, the default calendar app is limited and Siri is improved, but remains less useful than it should be.
The iPhone 5s has an updated A7 processor, and is the first smartphone on the market to use 64-bit architecture. Apple says it is up to twice as fast than the A6 chip used on the iPhone 5.
However, side-by-side with the iPhone 5, it is hard to spot the differences. General performance is slightly improved, but there is not a huge difference between the two, and most of iOS 7's animations look exactly the same.
The real advantage of the A7 processor in the iPhone 5s will be seen in the coming months, as more applications are developed to take advantage of its power.
Perhaps more important than the A7 processor is the iPhone 5s' M7 "coprocessor". Apple claims it is a "sidekick" to the A7 chip, designed to measure motion data from the phone's accelerometer, gyroscope and compass. This works as advertised, but again, it is not open to third party apps.
Camera & battery life
The camera on the iPhone 5s still uses an 8-megapixel sensor but now has a 5-element lens with an aperture of f2.2.
Apple says the surface area of the sensor is larger than its predecessor, and the pixels are larger at 1.5 microns. The difference between the iPhone 5 and iPhone 5s for daytime shots is not too apparent, but low-light performance is significantly improved.
Low light photos are also aided by a new camera flash on the iPhone 5s. It has been upgraded from single-LED to dual-LED and Apple says it is the first with different colour temperatures on each LED. While it produces better results, it is no substitute for a proper Xenon flash.
The iPhone 5s boasts a few new camera features. A new burst mode can take 10 photos in a second and automatically select the best shots, while a slow-motion recording mode can capture 720p HD video at 120 frames per second.
Apple says the iPhone 5s' battery will last for up to eight hours on 3G, and up to 10 hours of 4G and/or Wi-Fi Internet use, while talk time is listed at up to 10 hours.
However, anyone who uses the device extensively throughout the day will be disappointed to learn they will need to charge before a night out to avoid a dead iPhone.
The final word
Apple's iPhone 5s has a small screen by 2013 standards and is unlikely to attract users switching from large screen Android devices, but remains the best smartphone Apple has ever released.
The useful fingerprint sensor, a faster processor and improved low light camera performance will keep most iPhone users satisfied.