An almost identical model to the Touch Dual, HTC's Touch Dual 850 is a Telstra-exclusive release in Australia. Running on the 850MHz HSDPA band (hence its name), the Dual 850 uses a compact QWERTY keyboard instead of the Touch Dual's standard nine-key keypad.

After the original launch of it back in 2007, HTC sought improvement in the Touch Dual models, and they have greatly improved the TouchFLO interface. Although both models look very similar to the original Touch they are slightly thicker and longer than their predecessor thanks to the slide out keypad.

The Touch Dual 850 uses a slimmed down version of a QWERTY keyboard, instead of the regular Touch Dual's nine-key layout. The 20-key keypad loses the Internet Explorer, Messaging and Start menu buttons, but we feel that it's a much better proposition than a regular keypad. This is intended to be a business device and despite the buttons being small and flat, the presence of a QWERTY keyboard is a plus. There are keys for commonly used functions like space, delete and caps lock and the dictionary works quite well – simply use the comfortable five-way navigational pad to scroll through various words while typing.

Surrounding the navigational pad is answer and end call keys while the power button has conveniently been moved from the top to the right side – on the Touch Dual it was difficult to press when the slider was open. The dedicated camera button and a volume slider all remain, while the stylus is neatly hidden into the bottom right-hand corner.

TouchFLO is of course present on the Touch Dual 850. Most of the same features remain from the original Touch but the home screen now has a sound mode tab; a convenient task manager application which displays memory information and larger start menu icons – meaning you won't have to use the stylus very often. The phonebook also has an alphabet on the right side, so it's easy to narrow down contacts for quick access. You'll still have to use a stylus for other tasks, such as the calendar, but overall the user experience of TouchFLO has been greatly improved.

The Touch was lambasted for its lack of 3G connectivity, so HTC has added HSDPA capabilities to the Touch Dual. Unfortunately, Wi-Fi has been omitted and this may be a deal breaker for many users. On the upside, the Touch Dual 850 has A2DP Bluetooth support, which was missing from the original model.

As a multimedia device, the Touch Dual 850 is solid, but not outstanding. The lack of a standard 3.5mm headphone jack hasn't been corrected, and although the multimedia menu is well designed and easy to use without a stylus, finger touches and swipes are often inaccurate and fiddly.

In better news, the Touch Dual 850 has a 400MHz processor and 128MB of RAM. Most menus load swiftly, while scrolling through long lists and opening large files doesn't result in too long of a delay.

The Touch Dual 850 has a 2-megapixel camera with a self-portrait mirror, but the lack of flash means night-time photography is near impossible. It includes a two- or 10-second self-timer, white balance adjustment and several effects.