Thee popular TyTN II was the smartphone of choice at PC Authority for a long time until the A-Listed Nokia E71 stole its crown. And it’s still, in our opinion, one of the best Windows Mobile smartphones around. Its heir, the Touch Pro, aims to go one better: it takes the best of the TyTN II and combines it with the touchscreen gilding of the HTC Touch Diamond in an effort to come out on top once again.

The star of the show is the phone’s keyboard, which slides out from underneath the screen with a buttery smooth action and a firm thunk. This makes the Pro a chunky phone at 18mm thick – the Diamond (11.4mm), Nokia E71 (10mm) and the iPhone 3G (12.3mm) are all slimmer – but it does mean the Pro is much more usable than its sibling.

The keyboard isn’t quite in the same league as the BlackBerry Bold , but it’s at least as good as the keyboard on the Nokia E71. It’s sensibly laid out, too. Normally, phone-based keyboards lack such luxuries as Tab, Caps Lock and Ctrl keys, replacing them instead with brain-curdling key combinations. This keyboard has dedicated keys for each, plus a fifth row for numbers above the letters.

Like the Touch Diamond, the Pro is equipped with HTC’s new touchscreen interface, TouchFlo 3D. This replaces the awkward Today screen of Windows Mobile 6.1 Professional with something far more attractive and suited to finger-driven operation. A large flip-chart-style clock greets you when you turn it on, and it’s complemented by equally attractive home screens for email, text messages, contacts, web browser, photos and video, music, weather and settings.

Plus it’s far more responsive on the Pro than it was on the Diamond that we first reviewed. Admittedly, HTC has since updated the ROM for the Diamond, so owners don’t have to suffer its previously excruciating performance, but the Touch Pro feels slightly nippier still. We can only attribute this to the increased helping of RAM, up to 288MB from 192MB, since the processor is the same 528MHz Qualcomm unit.

The 640 x 480 screen is as glorious as it was on the Touch Diamond too, and the web browser – Opera Mobile 9.5 – continues to impress, allowing you to zoom in and out of fully-rendered web pages and pan around at will. The Pro, like the Diamond, has an accelerometer that detects the orientation of the phone, rotating photos and web pages automatically as you move the handset from portrait to landscape mode in your hand.

And the Touch Pro is crammed to the gills with smartphone hardware. Where you can get a signal, it will let you browse the internet at speeds of up to 7.2Mb/s; there’s Wi-Fi, Bluetooth 2.0, GPS and an FM radio tuner; plus a 3.2-megapixel camera on the rear (with LED flash) and a VGA camera for video calls on the front.

Call quality is good, the camera takes better photos than the Diamond, and the GPS receiver works reliably, regularly achieving satellite reception in less than a minute. It doesn’t have much Flash memory built in – just 512MB – but a microSD slot allows you to add much more than that if you want. It’s arguably preferable to the Diamond’s more generous, but non-expandable, 4GB allocation.

But all this comes at a cost. The biggest problem with the Touch Pro is battery life. Despite the fact it has a more capacious (1340mAh) battery than the Diamond, you’ll be lucky to get more than 24 hours’ life out of it with push email switched on and just light data and call use.

You can extend it, however, by choosing to manually retrieve email – in this case battery life is far more impressive at around two to three days – but in doing so you lose out on one of the key advantages of owning a Windows Mobile smartphone: instant email delivery.

The other issue with the Touch Pro is cost. Without a contract this phone is extremely expensive at $1175. This means that, even when the networks take it on, it will be available for free only on expensive plans, and is likely to cost more than $400 on standard contracts.

Both the high price and low battery life count against the HTC Touch Pro, especially when placed next to the BlackBerry Bold and Nokia E71. If you don’t have any driving need to buy a Windows Mobile device, but want keyboard entry, then they are certainly superior devices.

However, the Touch Pro is a highly capable smartphone. It has a fantastic screen, web browser and all the features you could possibly want. It’s lovely to use and an effective pocket computing and communications device. Combine all those benefits with the best smartphone keyboard we’ve come across bar the E71 and Bold, and it’s the obvious choice if you need a Windows Mobile-based phone.