It's been around seven years since O2 launched its Xda range of own branded smartphones, but the freshly squeezed Zest is the first one aimed specifically at Pay and Go users, although it is available on pay monthly too. The Zest also breaks with tradition in that it is actually built by Asus, whereas most other Xda devices are rebadged HTC models. Priced at £249.99 on O2's Pay and Go tariff, the handset is relatively cheap as smartphones go, especially as it packs in a decent range of features including HSDPA support and an onboard GPS chip.
Design-wise, the phone isn't what you'd call a looker. It's more functional than flash, with its wide and thick dimensions making it look rather squat. And while the glossy black finish on the front and back initially looks quite appealing to the eye, it collects more finger prints than the cast of CSI making it quickly look pretty grubby and in need of a wipe down. It's not all bad though, as the handset's small size makes it quite comfortable to hold and O2 has added a simple, but very useful, sliding button on the side that instantly takes the phone in and out of standby mode.
As with most of the current batch of Xdas, the Zest is built around Windows Mobile 6.1. There's plenty of debate about the benefits and draw backs of Windows Mobile: some like its broad range of features, while others hate its unwieldy user interface.
We're certainly not keen on the standard look and feel of Window Mobile, so it was a relief to see that O2 has kitted the Zest out with its own user interface (which is actually a tweaked version of SpB's Mobile Shell). This is essentially an overlay that sits on top of Windows Mobile and presents you with a simplified home screen and a 3D-style menu system with chunky buttons that are easy to poke with your finger. These menus are surprisingly responsive (more so than those found in HTC's similar TouchFlo interface) and actually do a decent job of making Widows Mobile a bit more user friendly.
In fact, the handset is one of the most responsive Windows Mobile handsets we've used recently thanks, no doubt, to it's speedy Marvell TavorP 624MHz processor. Screen updates are pretty much instantaneous and there's very little slow down evident even when you're running programs in the background.