A week with: iPhone 5s - undoubtedly at the frontier of what a smartphones is

What is it?

Depending on who you ask, the iPhone 5s is either the last word in must-have gadgetry or proof that Apple has finally run out of ideas. Launched alongside the 5c, its less expensive (I couldn't say cheaper) little brother, the 5s is a somewhat understated upgrade from last year's model.

Wait, so it's no good?

Of course not, it's absolutely amazing. It may be a cliché but Apple simply doesn't make bad phones: a new pair of processors means there's never any lag; the aluminium construction feels fantastic (I now know what "chamfered edges" are and have an urge to take a file to sharp corners everywhere) and even for an Apple novice such as myself, the operating system is intuitive to use.

That being iOS 7, the operating system that destroyed everything people loved about the iPhone?

Yep, that's the one – and not a moment too soon: the iPhone has been looking stale since 2011. The naff 3D effects and glossy finishes have finally been replaced with more minimalist icons and a somewhat Day-Glo colour scheme. The latter takes a bit of getting used to, but it's far from being the visual monstrosity that some bloggers labelled it.

The real important additions for iOS 7 have been features: there's a new control centre (swipe up anytime to get quick access to stuff like Wi-Fi and music playback); improved multi-tasking (double click the home button to see, and shut down, running apps); and a whole host of minor tweaks, many of which were long overdue.

So I should just update to iOS 7 on my iPhone 5 and call it a day then?

Maybe. The 5s is identical to the 5 in many ways but there are subtle changes, some of which, as it were, are bigger on the inside, including Touch ID (Apple's new fingerprint sensor that's integrated into the home screen) and a new pair of chips inside powering the thing – the A7 and M7.

Touch ID had most of the attention for its perceived security flaws but that's missing the point. It's a system that's about convenience rather than security and in that it succeeds wonderfully: using it to unlock your phone or authorize iTunes downloads soon becomes second nature, whereas determined hackers – well, they crack everything eventually.

The processors are possibly the more exciting bit of kit, but they've yet to come into their own. The M7 is dedicated to monitoring motion data and helps save on battery life (though you still only get a day's use), while the A7 is 64-bit; an architecture previously reserved for desktop computers that's 40 per cent faster than the A6. But both will require software written specifically for them to take full advantage of their power.

But what about now, should I buy it?

If you're on a top-end Android then probably not – there's nothing specific to tempt you over and if you're heavily embedded in Google's OS then there's quite a bite of inertia (your accounts, your apps) that makes switching a pain.

If you already own an iPhone then really it depends on your budget and how much you care. The 5s is undoubtedly at the frontier of what a smartphones is – offering a bunch of tiny ways to make your life just that little bit smoother – but it costs. It costs quite a lot.

And, as ever with Apple, although this is the best iPhone there is, that's only until the next iPhone comes out.