It's been a long time since Apple was under this much pressure to impress with a new iPhone. After last year's rather straightforward upgrade, the Cupertino company needed something special, and something to fight back against the moves being made by its rivals.
The iPhone 6 and the iPhone 6 Plus are Apple's counter-punches, but how do they stack up against each other? And which one should you be spending your cash on?
Read our hands on: iPhone 6 review
iPhone 6 vs iPhone 6 Plus: Design
The world's iPhones have got thinner and lighter since 2007 but this year Apple has really worked some iPad Air-style magic on the dimensions of its latest handsets. The 4.7-inch iPhone 6 is just 6.9mm thick (shaving another 10% off the already slim 7.6mm iPhone 5S) while the 5.5-inch iPhone 6 Plus has a thickness of just 7.1mm.
The differences over the 2013 batch of iPhones is noticeable, and Jony Ive's team have rounded the corners of the iPhone 6 and 6 Plus to accentuate the slimness of these devices, as well as adding more premium metal to the mix.
The familiar iPhone button layout has been rejigged to allow for this new super-thin frame. Most significantly, the power button moves from the top to the side, while the bands running across the top and bottom of the devices are introduced to improve reception and connectivity.
These are two almost impossibly svelte handsets, with the iPhone 6 offering a slightly thinner design than its more expensive iPhone 6 Plus sibling. If you're a phablet fan or have particularly large hands, the bigger model is the one you'll have your eyes on. The same gold, silver and grey options are available across the board.
iPhone 6 vs iPhone 6 Plus: Screen
The screen is where we find the biggest gap between the iPhone 6 and the iPhone 6 Plus - it's the main distinction between the models. The iPhone 6's display measures 4.7 inches corner-to-corner at a resolution of 1,334 x 750 pixels (or 326 pixels-per-inch).
The 6 Plus ups this to 5.5 inches and a resolution of 1,920 x 1080 pixels (401ppi). These figures put the iPhone 5S firmly in the shade, with its 1,136 x 640 pixel, 326ppi display.
All that means you get more pixels on the 6 Plus spread across a larger area. Website text will be bigger, movies can be viewed from further away, text will be sharper, and so on. It also makes the device harder to hold in just one hand, but the one-handed mode built into iOS 8 should be able to alleviate some of those problems. The weight of either the iPhone 6 or the iPhone 6 Plus shouldn't be a problem, at least.
One extra benefit you get from the additional screen space on the iPhone 6 Plus is the ability to run apps in landscape mode, iPad-style - it's a bonus for anyone who wants more room to work with on their handset. If you use any serious productivity apps on the go then bear this in mind, though compatibility varies between apps.
iPhone 6 vs iPhone 6 Plus: Camera
Both of the new iPhone models feature the same camera lens technology. That means an 8-megapixel shooter (as with the iPhone 5S) but an improved f/2.2 aperture and processing algorithms, so your pictures are going to look better than ever in all conditions. Bear in mind that the iPhone 6 will be easier to handle with one hand when framing shots, but the iPhone 6 Plus will give you more viewfinder screen space to get your image lined up correctly.
The iPhone 6 Plus features optical image stabilization (OIS), while the iPhone 6 only has regular image stabilization. Also built into the iPhone 6 and the iPhone 6 Plus is the NFC technology required for Apple's new mobile payments system, so you can use either phone to make contactless payments when you're out and about. The iPhone 6 is a little more pocket-friendly, which can help if you want to travel light.