Apple iPhone 4 review

Apple's hotly anticipated new iPhone model is finally here, introducing an updated version of the operating system plus a refreshed hardware design with high resolution screen and support for high definition (HD) video recording.

Available now from Apple and several UK mobile networks, the iPhone 4 builds on the consumer-friendly features that made previous models a hit with buyers, such as its touch-driven user interface and close integration with Apple's iTunes music service, not to mention the burgeoning number of apps available for it.

It also adds some features that may make the iPhone fit better into an enterprise IT environment than earlier models, more of which later.

For existing iPhone users, the main attractions of the new model will probably be its HD video recording capability and the FaceTime app for making video calls – just so long as the people you are calling also have the new iPhone.

Other than these features, we found the iPhone very similar in use to previous models, despite the new iOS4 operating system. The user interface appears to have changed little since the very first iPhone model, and the supplied applications are likewise mostly the same.

This is not necessarily criticism, but users who already have an iPhone 3G or 3GS may want to think twice before rushing to replace it with this model, unless they can get a good deal on the upgrade.

Those who have not previously owned an iPhone should be warned that the handset is tied intimately to Apple's iTunes service. This is the only mechanism through which consumers can purchase and download applications and music.

However, the iPhone itself must also be connected to a Mac or Windows PC running iTunes to be activated before you can use it. While most potential iPhone buyers are likely to have a Mac or PC, making this a requirement seems to be taking things a bit too far.

The iPhone 4 is available with twice the Flash storage of previous models, in 16GB or 32GB versions. We looked at a 32GB model connected to O2's network.

In design, the iPhone 4 is slimmer and flatter than its predecessors, lacking the slightly bulging rounded back of earlier models. In fact, Apple claims it as the world’s thinnest smartphone at just 9.3mm thick. It also feels more solidly built than the earlier models, although at 137g, it is just 2g heavier, and is more comfortable to hold.

Our review unit came in the glossy black casing that is currently the only choice, with a white version expected to be available from July. It has a stainless steel band running round the edge of the casing that also doubles as the antennas for the wireless radios.

Much has already been written about the problems some users have had with signal strength due to this design, but we encountered no such difficulties during testing. No matter how we held the device, it did not seem to affect the signal strength indicated, and we were able to make and receive voice calls perfectly well when holding the iPhone in a left-handed grasp.

The steel band is punctuated by controls, with volume up/down and a mute switch on the left side. The top edge has the on/off button, 3.5mm audio jack socket and a microphone used during FaceTime calls. All those controls are also made of steel and have a reassuring rugged, industrial feel.

On the right edge is a pop-out tray for the micro SIM, while the bottom edge of the device has Apple's 30-pin dock connector, the main microphone for voice calls, plus a speaker.