With the launch of the iPhone 6 in September, Apple finally caved into pressure from smartphone users and increasing competition from rival vendors and launched a larger format handset.
With the release of the latest version of the iOS operating system on 20 October, iOS 8.1, the iPhone 6 and iPhone 5S both have access to extra features, making them even more attractive smartphones in their own right.
Apple Pay is now live in the US as part of the iOS 8.1 rollout, although UK users are still unable to access the service. iCloud Photo Library has also launched in beta, letting users manage a single photo library across multiple devices using iCloud storage space.
Those with a Macbook running Yosemite will be able to make use of new Continuity features included in iOS 8.1, including SMS relay, allowing Mac users to receive messages from non-iPhone users on their Apple laptop or desktop. iOS 8.1 also addresses problems with group messaging, Bluetooth connectivity, a screen rotation bug and a video playback issue in Safari.
The above all make either device a great choice for current Apple fans or those new to the Apple family, looking for a smartphone that offers a user-friendly experience, great performance, and a thin and light design.
But as you can get all these new features on your older iPhone 5S, is it worth moving up to the iPhone 6? We've been using the iPhone 6 with its 4.7in screen for a few weeks now, giving us plenty of time to test out all the features, get used to the larger build and compare the new model to its predecessor, the iPhone 5S, to see whether it's worth upgrading.
Design and build
The iPhone 6 measures 138x67x6.9mm and weighs 129 grams. It has rounded corners as well as a lightweight build, meaning it's comfortable to hold for long phone calls and while typing or viewing media, for example.
The older iPhone 5S is much smaller by comparison, measuring 124x59x7.6mm and weighing only 112g. However, compared to the iPhone 6, the 5S seems much more hard edged, meaning the old model is much less comfortable to hold for long periods than its new sibling.
Apple has also taken account of one-handed use in the longer design of the iPhone 6. Tapping the home button will now temporarily roll the screen down so that content in the upper portion can be reached without overstretching your fingers, meaning it's easier to use the phone with just one hand.
As well as the larger casing, Apple has moved the iPhone 6 power/standby button to the right-hand side of the device - on the 5S model, this sits at the top of the phone.
Both models feature the Nano SIM slot on the right, and the ringer on/off switch and volume controls tothe left (the volume up button can also be used to take pictures from the camera app).
Both also have a 3.5mm headphone jack, microphone, Lightning charging port and speaker located on the bottom. The home buttons on the iPhone 6 and 5S both have the Touch ID fingerprint sensor built in, while on the back of both is the dual flash and camera lens.
Apple also offers both in three case colour choices: gold, silver and space grey.
We found that the speakers and microphone are noticeably better quality on the iPhone 6. With the 5S, we couldn't get a high enough level of volume for video or music playback, but with the iPhone 6 you do get a better volume, meaning you don't need to pack travel speakers for a bit of music or video playback on your next trip. We also found the mic on the newer device was better at picking up sound for audio recordings, even when some distance from the source.
Both models have the standard high-quality build we have come to expect from Apple. The aluminium casing gives a premium feel and the glass screen is integrated seamlessly into the phone's casing. However, the iPhone 6 hasn't improved the durability of the screen, and even in our short time of using the new model we've found it prone to developing nicks and scratches to the screen, so investing in a clear screen protector or full protective case is a must.
Winner: iPhone 6
Apple has packed the 4.7in Retina HD display found on the iPhone 6 with 1334x750 pixels, at 326ppi. The screen is an LED-backlit widescreen display with multi touch and in-plane switching (IPS), which offers a decent image from a wide range of viewing angles.
The iPhone 5S features a 4in Retina display with a 1136x640 resolution at the same 326ppi.
The colours on web pages, games and video are bright and vibrant on both models, while text is clean and crisp. The high-quality in-plane switching (IPS) panels are 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.
In addition to offering users a larger display, the iPhone 6 lets you pick between a standard or zoomed view for the home screens, which both take full advantage of the larger 4.7in screen. Standard mode displays the icons in normal size, so you can fit six icons down each home screen compared to only five on the 5S, while zoomed displays the icons in a larger format. Both still fit four icons across the screens.
The zoomed view on the iPhone 6 will also display text in a larger format, ideal for anyone with less than perfect eyesight, while standard displays more text on the screen when reading emails or messages, for example.
Winner: iPhone 6
Next: Performance and security