The original Sony Ericsson Xperia arc impressed us with its slim design and latest version of Android, but we were worried that its single-core processor might be underpowered compared to the slew of dual-core smartphones appearing on the market. The follow-up to the Arc goes some way to addressing the power deficit, but instead of doubling the cores Sony Ericsson has fitted a faster 1.4GHz single-core processor.
Current Xperia arc owners don't need to feel they're missing out, though, as the Arc S isn't hugely different from the original. It still runs Android 2.3 and has the same 4.2in screen, and despite the 40% faster CPU the S doesn't feel any quicker than the original Xperia Arc - Android runs smoothly, but we didn’t see any particular improvement when multitasking.
The phone has a sparkly plastic rather than metal casing, which may put some people off, but it also helps keep the weight down - at only 114g it's one of the lightest big-screen smartphones we've used. Sony Ericsson has generously included an 8GB microSD card, and there's 1GB of internal memory.
We were expecting the faster processor to reduce battery life, especially as the Arc S has the same battery as the Arc. However, in our light usage test where we play an MP3 file on a loop, the phone lasted for almost 40 hours - a seven hour improvement on the Arc. Depending on your use of 3G, GPS and Bluetooth, the Arc S should last a full day or even two without charging. Installing apps such as Advanced Task Killer and Juice Defender should help reduce the need for charging too.
As we went to press, Sony Ericsson's website still mentions USB Host support on the Arc S page, which is rather misleading. The phone itself doesn't support USB OTG (On-The-Go) - the official name for USB host support. Instead, you have to buy an optional LiveDock (part code: DK10, £30), and it only supports keyboards, mice or gamepads, so you won't be able to use it to attach storage devices, for example.