Camera: Pixel frugal or pixel poor
Apple and HTC are big believers in the idea that cameras aren’t about megapixels.
So while rival flagships from Samsung, Sony and LG have 12, 16 or even 20MP cameras, the iPhone 6 sticks with just an 8MP sensor - exactly the same size as that on the iPhone 5S, the iPhone 5, and the iPhone 4S.
That's not to say that it hasn't been improved. Each individual pixel is now bigger, which should result in more detailed photos in good light, plus it should also be able to focus faster as it uses in-sensor phase detection, much like the Samsung Galaxy S5.
The iPhone 6 also has image stabilisation - software-based rather than the physical kind on the 6 Plus or LG G3 - which should improve low-light photography, and it can also now record super slow-motion video at 240fps in addition to capturing standard 1080p footage.
The HTC One M8 is even more extreme in its pixel hatred, bringing a mere 4-megapixel sensor to the smartphone party. It likes to call its megapixels UltraPixels, but all that really means is that the sensor pixels are a bit bigger than those of most mobile phones. If a giant DSLR uses megapixels, they’re good enough for the HTC One M8.
It doesn't do this just on a whim, though - the idea being that a lesser number of bigger pixels will result in better low-light photography, at the expense of being able to blow your pictures up big. And it works, with the M8's low-light performance beating that of almost any other phone.
It also has a rather unusual trick up its sleeve: it uses two sensors and two lenses to help produce photos with a 3D element and ones with blurred backgrounds – making your photos look as though they’ve been taken with a much fancier camera and a much fancier lens. It doesn’t always work, but with a bit of luck it can really pep up your portraits.
So both cameras have their special skills, but ultimately, the verdict's out on this round until we've really put the iPhone's camera through its paces.
READ MORE: Apple Watch hands-on review
Power and storage
The HTC One M8 is an excellent performer among Androids. It has a quad-core 2.3GHz Snapdragon 801 CPU with 2GB of RAM and we've never known it to be fazed whether by high-end games, multi-tasking or full HD video.
Just look at the numbers and it seems like it should cream the iPhone 6, which has a dual-core CPU. It’s not quite that simple, though.
The iPhone 6’s new Apple A8 processor is a few steps more advanced than the Snapdragon 801. First, it’s 64-bit where the Snapdragon is fundamentally a 32-bit processor.
The way it’s made is also more advanced. Where the 801 uses a 28nm process, the iPhone 6 is a 20nm CPU. And, yes, the lower the number the better.
Without wanting to dig too deep, this means the transistors that make up the processor are 20 nanometers in size in the iPhone. And smaller transistors make a processor more efficient.
Comparing an iPhone with an Android is never going to be 100% fair, though, as their power is used in different ways. For now, we'll settle for saying that we expect the iPhone to at least match the M8.
Of course the other type of power is that which you get from a battery, and the M8 excels here too. We generally get a full day's use from it - and trust us, we're the kind of people who really do put a phone through its paces. Plus, it has a superb battery-saving mode which can eke hours more out of a mere few percent.
It's hard to say how the iPhone 6 will fare, but Apple itself only claims 10hrs of talk time (HTC reckons 20hrs for the M8), so we'd be very suprised if it ends up topping its rival on this front.
Finally, the M8 also has one other thing the iPhone 6 lacks: a microSD slot. No iPhone has ever offered one of these, and there are no signs that’s going to change any time soon.
However, you can get a 128GB iPhone 6, which will store enough cat photos and episodes of Dawson’s Creek to fill a month’s worth of miserable, lonely evenings. Of course, you’ll probably have to sell your kidneys and most of your family to afford a 128GB iPhone 6, but that’ll just key you into Dawson’s angst all the more.
Stepping back into the real world, a 128GB iPhone 6 will cost you £700. That’s a £260 upgrade, while a 128GB microSD card costs about £70-80.