Later in this review we're going to be using words like 'incredible', 'ingenious' and 'astonishing'. We'll be so over the top in our compliments you might call into question our impartiality, and wonder if we should rename the magazine Sony Pro. So before we go overboard, we'll start with the criticisms.

To begin with, the screen. This takes a different approach to conventional TFTs, with Sony opting for LED technology rather than cold cathode fluorescent. The end result in this VAIO's case is a grainy appearance - load up Word, for instance, and you'll see a mottled effect. We're not convinced about the keyboard either. With our hands in the touch-typing 'home' position (index fingers resting on the F and J keys), we found the palm of our hands stretched beyond the edge of the casing. This lack of space also means the mouse buttons are very slim.

Miniaturisation extends to other areas of the design too. The built-in optical drive proved quite irritating to open, as the eject button is minuscule. This isn't the coolest running of notebooks either. When you start working the processor or hard disk - playing MP3 files is enough - the bottom left-hand corner becomes hot, and that leads to the fan kicking in.

Other faults? Well, it doesn't have a huge number of ports: two for USB 2, another for mini-FireWire, plus the standard connectors for the modem, 10/100 Ethernet and VGA output. The warranty is a little disappointing too: one year's return-to-base cover is all you get^^^CHECK^^^^^. And as it relies on Intel's integrated GMA 950 graphics, this VAIO is never going to cater for gamers.

Nor is it for people looking to encode large chunks of video quickly. The 1.2GHz ultra-low-voltage Pentium M chewed through our tricky Procoder test in just under 29 minutes, compared to around 12 minutes for the latest dual-cored Pentium D desktop PC. In everyday use, though, this remains a fast notebook. A score of 0.57 is only a fraction behind a respectable desktop system, and even when we used the TX1XP away from the mains we found it fast enough.
And it's when you unplug this notebook that it really excels. The 7,800mAh battery Sony supplies as standard kept the VAIO going for an astonishing six hours, 57 minutes in our light-use test. If you're willing to spend a further $599 on the extended life battery, the news gets even better: a battery life of 11 hours, 35 minutes under light use breaks all records.

Then again, the extended battery does have a 13,000mAh capacity, weighs 548g all on its own and measures 44mm tall. It inevitably destroys the sleek shape of the VAIO, but we still found it comfortable to use on the lap and on a desk. It's also worth noting that Sony's port replicator option - although basic, boasting just three USB ports, a VGA output and an Ethernet passthrough - is so shaped that you can slip the VAIO into it with the extended battery in place.

Even with the big battery attached, this notebook remains an object of beauty. This is partially due to its size - with a profile of just 26mm, it will draw many an admiring glance - and partially due to Sony's usual design skill. The matte black carbon-fibre lid only adds to the sense of class.

Whether the extra-thin lid will result in more broken screens is more difficult to say. It's very flexible, but this isn't always a bad thing; if you close the lid quickly, without realising a pen was lying on the keyboard, that flexibility could mean the screen doesn't break.

Although we criticised the screen for the mottled effect when working, it did prove highly effective when watching DVDs - plenty of detail in shadow, no obvious smearing and accurate colours being three highlights. It's made all the more appealing by its 16:9 aspect ratio. But what makes the TX1XP so incredible is the inclusion of an optical drive into such a tiny chassis, while keeping the weight to 1.4kg. The drive is even capable of burning DVDs, with support for dual-layer discs being a particular bonus.

Press the AV Mode button beneath the screen and you can even watch films without waiting for Windows to load up. The speakers are loud but inevitably tinny, so you'll probably prefer to use the front-mounted headphone jack. This is kept company by a microphone jack, volume-up and -down buttons, plus a handy mute button. We also appreciate the hardware switch for quickly activating the VAIO's two wireless capabilities: 802.11b/g WLAN and Bluetooth. But the biggest surprise is the inclusion of an SD slot to keep the more predictable Memory Stick slot company. Around the side, there's a Type II PC Card slot.

For Sony to squeeze all these features into a notebook so light and compact is quite simply a feat of genius. When you add the amazing battery life, it's easy to overlook the VAIO's failings. Although it can't quite usurp the Dell D410 from the A List - this just offers too much value for money in comparison - the TX1XP is the best option around if you want a built-in optical drive in a package this small.