iPhone 6 side view
iPhone 6 is longer, wider and thinner than Apple's 5SApple

iPhone upgrades are often anticlimactic, with Apple preferring to build and improve steadily rather than mess with a winning formula - but the iPhone 6 represents that rare leap into the wild blue yonder. The latest iPhone 6 offering has an ion-strengthened screen, and supports mobile payments, but does all that make it worthwhile to upgrade from the exemplar iPhone 5S?

Design

With Apple deciding to get on board the super-sized smartphone craze, the iPhone 6 is a fair bit larger albeit thinner (6.9mm) than its 5S predecessor. If you believe bigger is better, then opt for the iPhone 6.

Colour-wise there's nothing to separate them, both available in only gold, silver, and grey.

Screen

The iPhone 6 matches the 5S with a pixel density of 326 pixels per inch (ppi), but ups the resolution to 1334 x 750. At 4.7in, the iPhone 6 screen is bigger than the petit 4in offering of the 5S.

The new iPhone also has "ion-strengthened" glass screens which should prove ultra-scratch-resistant.

Hardware

The A8 processor that powers iPhone 6 is better than the A7 on which the 5S runs, boasting battery life improvements. The A7 is still highly-regarded hardware - it is ranked as one of the best packages out there - but the A8 has 25% faster processing power, and 50% faster graphics.

The latest iPhone also has Apple Pay, the fancy new NFC feature that enables mobile payments in just a few simple swipes.

At a reported 1GB, both the iPhone 6 and 5S are lacking in the RAM department.

Apple iPhone 5S (Silver) in the Apple Inc's media event, 2013.
The iPhone 5S is making way for the iPhone 6, Apple's latest flagship phoneReuters

Camera

The iPhone 6 rear camera is 8 megapixels (MP) with digital image stabilisation - matching what the 5S can offer.

High-definition video recording is offered at 60fps for 1080p video and 240fps for slo-motion. Other features include continuous autofocus, cinematic video stabilization, and time-lapse video.

The FaceTime HD front-facing camera has a new sensor which purportedly captures 80% more light. There's also better facial recognition for selfie enthusiasts.

Software

With the new HealthKit fitness monitor app and HomeKit internet-of-things hub, the iOS 8 operating system, which debuted at WWDC in June, is very much a look at where smartphone software is headed. As wearables and smart-everything becomes increasingly visible, Apple's newest software will come in handy.

Other improvements over iOS 7 include better maps, third party keyboards, interactive notifications, widgets, and family sharing.

Price

The iPhone 6 will be available for pre-order starting 12 September, 2014, and go on regular sale from 19 September. The phone will be available at first in the UK, US, France, Hong Kong, Canada, Germany, Singapore, Australia, and Japan.

The iPhone 6 starts at $199 in the US with a two-year contract, and then costs $299, or $399 for the respective storage options (16GB, 64GB, 128GB). UK pricing has yet to be confirmed. The phone comes in gold, silver, and space gray.

The iPhone 5S has replaced the fourth generation models as the affordable option - its pricing reduced to $99 with a two year contract in the US. Considering how much it cost just up until the iPhone 6 launch, the newly discounted 5S certainly looks appealing.

iPhone 6 iPhone 6 Plus iPhone 5S side by side
iPhone 5S, iPhone 6, and iPhone 6 Plus side by sideApple

Should I upgrade?

Probably, yes. This is the most substantial iPhone upgrade in quite some time, if ever. The screen is greatly improved, and the software introduces some features that look to stick around for the long haul. The advent of wearable tech and internet-of-things is upon us, and the iPhone 6 is a smartphone designed with that in mind.