Apple iPhone 4S

Is the newer, faster iPhone 4S any good? The answer mostly depends on your current phone.

At first glance, the iPhone 4S looks identical to the iPhone 4. It has the same slightly fragile glass front and back with a band of metal around the side and the same type of screen.

Take a closer look, though, and you'll spot a few small changes: the metal band is broken into four sections, not three, and the side volume and mute switches have moved a little.

The iPhone 4's metal band, which doubled as its antennae, was the subject of controversy when it launched, as some people found that gripping the phone caused it to lose reception. The 4S, though, has a new antenna design that uses two antennae, switching between them for better coverage.

The company says this makes for faster downloads. We didn't notice a speed boost but nor could we cause reception to drop by gripping the phone, as on the previous model. Nonetheless, we'd advise a side-hugging case to protect the phone's glass panels against accidental drops.

The screen is indistinguishable from that of the older model, with a pleasingly high resolution, and it isn't dim or hard to read, but rival handsets have since launched with bigger displays. Touch-response was as good as ever.

Inside the phone are three major upgrades. The rear camera takes eight-megapixel images that are among the best we've seen from a phone. They were easily as good as the pictures from a cheap compact camera, although like any small camera, image quality suffered in low light.

In video mode, the iPhone can record 1080P high-definition video making it good enough to replace a pocket video camera.

Another internal change is the phone's main processor, which has been upgraded to a dual-core model. We noticed an improvement when browsing very large websites and the biggest difference will be for people who enjoy playing 3D games, which work much more smoothly.

And then there's Siri, the ‘intelligent assistant' which lets users speak messages and instructions, and which worked surprisingly well. Although not terribly handy in public, we found it quicker to speak appointments than type them, and it understood even complicated instructions such as ‘add meeting next Wednesday 2pm physiotherapist'.

Disappointingly, the British version of Siri is hampered by being unable to do anything to do with the user's location (its American counterpart can find local businesses).

The new iMessage tool securely sends text messages over the internet rather than SMS. It worked brilliantly and seamlessly, but is also available as a free upgrade for iPhone 4 and iPhone 3GS users.

With iOS 5 it's possible to use the iPhone entirely without a PC or Mac – you can set up the phone, use it and purchase music and videos, backing up your information online over a wireless network. This won't be useful to everyone, but it's handy.

It isn't as impressive as the iPhone 4 was when first released, and unless you play lots of 3D games or want to dictate messages we'd say that iPhone 4 users need not rush to upgrade.

If, on the other hand, you're upgrading from an older phone, the iPhone 4S is a very good choice: it's powerful, packed with features and simple to use.