As promised, we were able to twist a few arms at Panasonic's Japan office to bring you the world's first hands-on preview of its new CF-U1 Toughbook PDA/Tablet PC hybrid, a full four months before it goes on sale there.

The latest small device to be powered by Intel's Atom processor landed with a thud on our desk this afternoon right on cue, suggesting that it might be slightly heavier than the 900g we predicted yesterday.

In fact, the chunky handheld weighs just over 1kg (1,060g), making it comparable to a typical subnote in terms of weight, in spite of its myriad USPs (that's 'Unique Selling Points' in the real world, BTW).

Loves filth

Where it really differs, as you can see from the photos of course, is in its construction. Panasonic has taken the Tablet PC concept and beefed it up with IP54-standard protection against dirt and water – it can survive the heaviest grime attack and being sprayed with water.

On top of that, it has a 16GB solid-state drive (SSD) instead of a spinning hard drive and drop protection that's guaranteed to handle a 120cm fall onto a hard surface. The other major build change to what has gone before is a full QWERTY keyboard to complement the touch-sensitive screen.

The 1,024 x 600-pixel screen also incorporates a polarizing filter that makes it readable even in direct sunlight. Otherwise, there's support for all flavours of Wi-Fi (including draft 802.11n), Bluetooth 2.0, optional barcode and fingerprint readers, GPS and camera if they're needed.

Horses for courses

As should be obvious from that lot, the U1's target user is the modern construction-site manager or anyone working in an environment that's likely to have a normal PC in fear of its life. This is clearly not a computer for the sedate stay-at-home user.

Nevertheless, the very consumer-oriented Atom is at its heart and that's what makes the U1 different from other rugged field devices. Aside from offering substantial battery life – more on that shortly – it's also powerful enough to run a standard PC operating system.

Panasonic has wisely chosen to offer both Windows XP and Vista (Business Edition), explaining that on-site workers can now take their office with them, instead of having to make do with simpler mobile platforms.

Whether that makes a big difference or not to likely users, we can't say – we don't have a handy building site for a field test – but we can evaluate what the U1 feels like from a more general point of view.

Getting our hands dirty

As might be expected, the U1 feels virtually indestructible in the hand. We actually dropped it several times with no noticeable effect to its operation, showing that the SSD and the other ruggedised components do their job as advertised.

Waterproofing clearly works, with even a dunk in the sink not a problem on this evidence. We'll take Panasonic's word (and that of the international standard IP rating) on the dust-proofing.

Although the machine is almost 6cm thick and weighs a full kilo, the sturdy hand strap works well, taking the load off effectively. It's similar to the strap on most camcorders and slips over the back of the hand to leave the screen pointing at the user's face.

From that position, using both hands on the keyboard is obviously impossible, but it's too wide to be used as a thumb-board and the buttons are too small for normal typing anyway.

The feeling we got was that the keyboard is really secondary to the screen, which is probably why a number-key-only option is available in Japan, at least.