If the P Series is a little rough around the edges where usability is concerned, what really sets it back is its performance. Notionally it's no worse than your average netbook, but then your average netbook costs at most £300 and often as little as £200. When you're spending as much as £800, netbook-like performance is harder to forgive.
From cold the device takes a leisurely minute and a half to be ready to use, a time that could be easily reduced were there not some somewhat pointless applications - such as the VAIO Gate toolbar - to load first. If all you want is the Internet then you do have option to load the instant-on web browser, which takes a more agreeable 20 seconds, but it's only really sufficient for quick tasks that one could easily perform on a smartphone instead - probably quicker, too.
More damning are basic things like adjusting the brightness of the screen. For reasons that aren't entirely obvious, manual adjustments of the brightness are incredibly laggy. This is particularly annoying if you want to adjust the brightness when watching a video, as it results in noticeable slow down. It's just as well there's an ambient light sensor to handle screen brightness the majority of the time.
Video playback on the device is also somewhat patchy. Both 720p and 1080p h.264 video can be played thanks to the video decoding abilities of the integrated Intel GMA 500 graphics, but it's not perfectly smooth due to a few dropped frames, a modicum of jitter (9ms on average) and some minor sync offset. It's still watchable, but only barely. Flash video, meanwhile, is no less picky. Standard definition is okay, but HD YouTube clips are a no-go and the BBC iPlayer's high quality videos aren't smooth in windowed or full screen mode.
Perhaps the most disappointing aspect, however, is the battery life. Because of the size of the P Series it has a measly 2,500mAh (19 Watt-hour) battery, which in our tests managed 193 minutes (3hrs, 13mins) of video playback and 222 minutes (3hrs, 42mins) of web browsing on Wi-Fi. Both these tests were performed indoors at 50 per cent brightness, too, so increasing brightness or using the notoriously power-hungry 3G HSDPA modem will only decrease these distinctly below-average figures further.
Despite Sony's design tweaks, the VAIO P Series is still an awkward prospect that's way too expensive to be a realistic purchase. Someone, somewhere might be able to make an argument for it, but for the most part it's an expensive indulgence - more so even than Apple's iPad.