On the hardware side of things Sony has stuck with Intel's Atom range, utilising a 1.86GHz Z540 CPU and the GMA 500 graphics core. These are matched to 2GB of RAM and a 64GB SSD, though the latter is limited by using the older PATA interface that's significantly slower than the SATA enabled drives you'll find in most notebooks and netbooks.
If you're wondering how this justifies the £799 asking price, look no further than the inclusion of integrated HSDPA, Wireless-N Wi-Fi, Bluetooth 2.1 and - somewhat superfluously by our reckoning - GPS and an eCompass. All of which means the P Series has almost every conceivable feature you'd demand of a mobile PC.
It's only almost, though, as physical connectivity leaves something to be desired. A couple of USB ports are adequate enough, as is the inclusion of an SD card slot and a separate memory card slot for Sony's own formats, but instead of an HDMI output we're treated to an awkward propriety VGA output that requires an adapter. Considering a mini-HDMI port would take up no more space, it would have been our preference.
Such complaints pale in comparison to the usability of the machine, though. We've already noted the difficulty of inputting text unless the device is set down, but even when it is typing is a tricky business. This is mainly due to the shallow, imprecise action on the keys, which must be hit firmly to guarantee keystrokes being registered. It's a shame really, as the layout and size of the keys are impressive considering the size of the device.
Joining the keyboard, and the aforementioned optical touchpad, is a trackpoint nestled between the G, B and H keys. It works pretty well and its three buttons, the middle one of which allows you to scroll when held down, offer up adequate feedback. It's still a significant compromise compared even to a netbook with a touchpad, though, or a touchscreen for that matter - for all ThinkPad users may disagree.
It's also worth noting that there are speakers on the P Series, but they're incredibly weak and are outperformed by many a mobile phone where volume and clarity are concerned.