Like the iPod touch and most modern PMPs, the PSPgo uses an internal, non-replaceable Lithium-Ion battery, now rated at 960mAh over the PSP3000's 1200mAh cell. The smaller screen size, the lack of UMD and some unspecified changes to the internal components mean that the PSPgo is more power efficient than its predecessor, but the lower capacity cell means that battery life is roughly the same. If you have a PSP you'll know that it's almost impossible to give solid figures on battery life, so much depends on screen brightness and the processing demands of the games you're playing (God of War: Chains of Olympus and Gran Turismo use a lot more juice than the more basic titles). I'm getting around five hours of decent gaming or movie watching out of the PSPgo, which is around iPod touch levels, but not as good as Nintendo's (rather less demanding) DS or DSi.
With UMD gone, a lot depends on Sony's online store. The first thing to note is that - in terms of firmware and software - the old and new PSPs are functionally identical. Anything you can download and play on the PSPgo, you can download and play on the PSP3000 or PSP2000, providing you have a memory stick with ample space. The second thing to note is that download speeds over the PSP's built-in Wi-Fi are painfully slow; anyone with any sense will hook up their PSPgo to a PC and purchase, download and transfer titles using the supplied Media Go application. As this also provides brains-free video conversion and music transfer, this is one of the few bundled media management apps that will actually see active use.
At the time of writing, the software line-up is respectable and growing, with major recent releases like Gran Turismo, MotorStorm: Arctic Edge, Need for Speed: Shift and FIFA ‘10 all onboard. There are still some inexplicable absences - no God of War: Chains of Olympus or Dissidia: Final Fantasy, for example - but classics like WipEout Pulse, LocoRoco2, Ridge Racers 2 and Ratchet and Clank: Size Matters can easily be found.
For all the talk about the huge range of games on the DS or the vast library on Apple's app store, it's still worth remembering that - when it comes to producing mobile versions of what you might call traditional console games - the PSP remains unchallenged. Sure, Firemint's Real Racing on the iPod Touch is great, but Gran Turismo looks significantly more impressive and - with physical, analogue controls - offers a more enjoyable and accessible drive. MotorStorm: Arctic Edge and WipEout Pulse leave any iPhone or DS rivals in the dust, and only a fool would even compare any iPhone action game to Chains of Olympus or Ratchet and Clank.