A year ago I compared the iPhone 5 and Samsung Galaxy S3 as the two best smartphones in the world - and in truth there wasn't a winner - but at no point was the HTC One X included in this debate. Now though, the HTC One is right in the thick of things, fighting it out with Apple and Samsung on behalf of a company in need of a lucky break.
Let's have a look at how Apple's new flagship smartphone - the Phone 5S - matches up:
Look and Feel
As processor speed and RAM become less important the more powerful and competent smartphones become, the battleground has shifted towards design. Fast processors and bags of RAM used to be enough to get enthusiasts to part with their money, but technology companies needed to sell to the mass market, to those who don't care for gigahertz and gigabytes.
For this end of the market, phone makers needed to make a product attractive and desirable, and as a result we have the iPhone 5S and HTC One - both pride themselves on their aluminium and glass bodies, industrial design and sense of worth somehow missing from much of Samsung's glossy plastic lineup - even if the latter are less prone to scratch damage.
The HTC One and iPhone 5S clearly came from the same school of thought, although at 4.7in HTC opted for a screen almost an inch larger, pushing overall weight up to 143g compared to the iPhone's 112g.
Measuring 4.7in with a resolution of 1080 x 1920 and pixel density of 489 pixels per inch (ppi), the HTC One's LCD screen is one of the best on the market, and although we're yet to see the iPhone 5S in person, it's screen is the same Retina display found in the iPhone 5. This means a resolution of 640 x 1136 and a pixel density of 326ppi.
Both screens offer more accurate colours than the overblown and sometimes cartoonish shades of the Samsung Galaxy S4 and its AMOLED screen - picking between the HTC One and iPhone 5S on the screen alone will be down to no more than size.
As I said above, the battleground has moved away from performance in recent months - at least away from comparing technical specifications - as all high-end smartphone are about as fast and responsive as each other.
Added to this, Apple never states the speed of its mobile processors or the amount of RAM used, so while the iPhone 5S's new 64-bit A7 chip is twice as fast as last year's A6, comparing it to the HTC One's quad-core 1.7GHz chip with 2GB of RAM isn't really possible.
The One could prove to be faster on paper, but in reality claiming one phone to be faster than the other is irrelevant as consumers prefer to compare camera performance and physical design. Put simply, both phones will run anything you have to throw at them.
The operating system is perhaps the biggest choice consumers face when buying a new smartphone. Screen size, design and camera quality all come into it, but once an OS has been chosen it becomes increasingly difficult to switch, as more non-transferable applications are purchased.
When I compared the iPhone 5 and Galaxy S4 earlier this year, I described Apple's iOS as ageing and in need of a refresh, and that's exactly what the all-new iOS 7 is. The biggest user interface change in its six-year history, iOS 7 ditches skeuomorphic design (torn pages in Calendar, a wooden bookshelf in iBooks) and replaces the visual metaphors with a clean, polished interface designed for the first time by head of industrial design, Sir Jony Ive.
A new piece of software for the iPhone 5S is TouchID, which works in partnership with a fingerprint reader located on the Home button. Users can use this instead of a PIN and password to unlock their phone, and as a quick way of entering their password when buying content from the iTunes Store.
In the other corner we have Android 4.2.2 Jelly Bean with HTC's Sense UI over the top. BlinkFeed is at the heart of the One's interface; a constantly updating news feed pulling in content from various news websites, agencies and blogs, as well as social content from your Twitter and Facebook feeds. For us, BlinkFeed feels a little unfinished and too chaotic to be used as a go-to news service, but it's interesting to see HTC make its own mark on Android.
One operating system isn't necessarily better than the other, but they are very different; Android is the more open and customisable option, while iOS is more restrictive but arguably more intuitive as a result.
HTC made headlines with the One's UltraPixel camera, which employs a new technology whereby images produced are only 4-megapixel, but each pixel is larger than other phone cameras, taking in more light and therefore improving quality - especially in low light conditions.
In our review of the HTC One we found the camera to be excellent, capturing impressive photos in low light environments, and producing results only slightly behind those of the hugely impressive Nokia Lumia 920.
Apple must have been paying attention, because the iPhone 5S also features larger pixels than before, while keeping image resolution at eight megapixels. There is also automatic image stabilisation, a faster auto-focus system than with last year's iPhone 5, and a larger f/2.2 aperture for capturing more light, but it's not as large as the One's f/2.0 lens.
Both smartphones offer a cutting edge balance between style and performance. Where the Samsung Galaxy S4 focuses more on features and speed than good looks and a sense of quality, the One and iPhone 5S use their design and excellent screens as much as their processors to convince buyers to part with their cash.
Choosing one over the other comes down to the operating system - and don't forget Google does a 'stock' Android version of the One without HTC's Sense UI. For my money, what we have here is the best of iOS and the best of Android and neither should be labelled a winner or loser.