Dell’s Latitude XT is a convertible Tablet PC design that makes a decent compromise between processing power and weight, an important consideration for a unit likely to be carried around while being used. It also sports good connectivity, with an integrated HSDPA modem as well as Wi-Fi and Bluetooth.

Shipping since the start of 2008, the Latitude XT is Dell’s first Tablet PC product, yet seems as mature a design as many that we have seen. The unit is a convertible model, which means that it can be used as if it were a conventional laptop, or else the screen can be twisted around and folded flat down over the keyboard to allow it to be used in slate mode for pen input or forms-based applications.

In tests, we found the Latitude XT light and compact enough to be easily held in the crook of one arm while using the pen for input, but at 1.6kg, we have doubts whether it is light enough for extended use like this. It is also costly compared with other Tablet PCs and standard laptops, but Dell said it is likely to be discounted from the list price.

In our experience, the 42Whr six-cell battery will provide power for less than three hours, so workers will not be able to spend too long away from a mains connection. Fortunately, the Latitude XT comes with a lightweight 45W mains adapter that is smaller than a packet of cigarettes and thus easy to carry with the system.

One interesting feature of the Latitude XT is its support for touch input as well as the active stylus that is standard with Tablet PCs. We were able to select and activate functions on the screen by fingertip or by tapping with the stylus, while the active stylus also provides the high resolution required for handwritten input.

Our review unit shipped with Windows Vista Business edition, which includes Tablet PC functions as standard. We were impressed by how accurately the Tablet PC Input Panel was able to translate our cursive input to text, at least when we wrote at an unhurried pace. However, we found the supplied stylus tended to stick slightly when writing on the screen, which made input hard work at times.

With 2GB memory, our review unit handled Vista well, although it was hardly a speed demon compared with lower specified systems running Windows XP. Vista’s own performance measurement tool rated the Latitude XT with a Windows Experience Index of 3.5, which is better than average and compares well with many other Vista systems we have tested.

Our review unit was based on a 1.2GHz ultra-low voltage Intel Core 2 Duo U7600 processor and had a 1.8in Samsung 120GB hard drive to keep weight to a minimum. This drive is also more durable than standard laptop drives, according to Dell.

The Latitude XT has comprehensive communication capabilities, with 802.11a/g/draft n Wi-Fi and a mobile wireless connection supporting 3G and HSDPA networks built in. A small antenna for the latter mobile wireless can be pulled out of the left-hand side of the chassis and positioned to improve signal reception. Dell supplies a Mobile Broadband utility that shows signal strength, so users can see how deploying the antenna makes a difference.

Using a connection to Vodafone’s network, we were able to get a HSDPA signal in central London that proved satisfactory for web browsing, but in some places outside the capital the laptop was unable to get a mobile connection at all. The SIM card to enable the mobile wireless service fits into a slot inside the Latitude’s battery compartment.

On top of wireless connections, the Latitude XT has both USB and IEEE.1394 FireWire ports for attaching peripherals, a slot for SD memory cards and an Ethernet port. A 54mm ExpressCard slot replaces the more common PC Card standard for adding adapter cards, plus there are audio jack sockets and a VGA port for an external monitor.

An optional £169 Media Base clips to the bottom of the Latitude XT and replicates all the laptop’s ports, plus it adds serial and DVI video ports and a DVD-RW drive.

The Latitude XT’s 12in display supports a decent 1280x800 resolution, and a row of buttons below it allow access to functions such as Outlook, Tablet Settings and screen rotation. There is also a fingerprint swipe scanner to support biometric security. By default, the screen switches from landscape to portrait orientation when moved from laptop to slate configuration.

As well as the active stylus, the Latitude XT has both a touchpad cursor controller and a trackpoint-style unit embedded between the keys.