Apple's iPhone 5S is the firm's latest flagship smartphone, and brings a range of new features to tempt users to upgrade or move over to the iOS family. We've put the 5S up against its predecessor, the iPhone 5, to see if it's worth upgrading from the 2014 premium model to its 2013 sibling.

iOS 9 offers improved battery life, bolstered security, context-aware search and a reduced file size to make installing the operating system an easier process for devices upgrading from iOS 8.

Key features include a smarter version of Apple's virtual assistant Siri, which gains a new user interface and the ability to be more proactive when handling the one billion requests it receives every week. Siri is able to deal with requests in a more contextual way, making suggestions based on a user's location or what is currently on the screen of an iPhone or iPad.

The new iOS also gives the native Maps app an overhaul, adding a new subset feature called Transit that provides specific information on public transport.

Enterprise users of iPads can rejoice at the addition of split-screen multitasking for iPads which, as one would expect, allows two applications to be squeezed on a single screen.

To make installing iOS 9 more practical, it has also been given the ability to delete apps then reinstall them automatically to make updating from iOS 8 a smoother process.

The iPhone 5S, shown above left, houses the new dual flash

Design and build
The iPhone 5S is pretty much identical to the iPhone 5 in terms of design and build, as you can see from our video below.Both iPhones have an aluminium case and glass screen, retaining the premium look and feel for the latest model so you're not faced with downgrading to the plastic iPhone 5C. Both devices are also comfortable to hold, with the same thin and light build, measuring 124x59x7.6mm and weighing only 112g.

On the outside, both iPhones feature a power button, with a SIM card slot on the right, a ringer on/off button and volume controls on the left (the plus button can also be used to take pictures from the camera app). There's a headphone jack, microphone, Lightning charging port and speaker on the bottom of the device. On the back, you'll notice the flash has changed and is now egg shaped rather than circular. This houses the new dual flash, which Apple has added to improve image quality in poor lighting conditions.

The only other difference is the home button, which stays in the same position and retains its circular shape, but it is now edged in stainless steel with a sapphire crystal. This change is due to the new home button housing Apple's new fingerprint scanner technology, which we'll come to later.

The iPhone 5S, shown above left, has a new home button

The only other difference in design is colour choice. While the iPhone 5 was only available in black or white, the iPhone 5S is available in three colour options: with gold or silver backs and a white front, or with a grey back and a black front. The gold option will no doubt prove popular with those posers out there who like a bit of bling in their lives.

Winner: Draw (unless you're from Essex, in which case the gold option edges it for the 5S)

Display
The iPhone 5S and iPhone 5 both feature a 4in Retina display with 1136x640 resolution at 326ppi. While the 5S doesn't offer an upgrade in terms of display, the iPhone smartphone screen is still a high quality display. The colours on webpages, games and video are bright and vibrant, while text is clean and crisp. The high-quality in-plane switching (IPS) panel is also evenly lit and the impressive viewing angles mean you can see what's on screen whether looking down from the top, up from the bottom, front or side on, or anywhere in between.

However, some 5S users or those who have upgraded their iPhone 5 to iOS 7 have complained about the new fonts, which are thinner and smaller, and the removal of boxes around menus, making text hard to read for those with visual impairments. So if you've got an iPhone 5 still running iOS 6, you might want to hold off upgrading if you're put off by the new pared-down interface.

Source: www.v3.co.uk