Audio, meanwhile, is also rather good. Ever since the Eee PC 1000H, Asus' has maintained a tradition of making its netbook speakers better than you have any right to expect for their size and the S121's are no exception. They manage a remarkable volume level without much distortion and relatively deep bass.
It's when we get to the internals that things get slightly disappointing. As mentioned before, the Atom Z520 (running at only 1.33GHz rather than the usual N270's 1.6GHz or N280's 1.66GHz and a slower 533Mhz bus speed to boot) means this isn't the speediest netbook around, and the rest of the spec is pretty standard. Hence you'll find the usual 1GB of RAM (just about enough to keep the installed version of Windows XP happy) and a vanilla 160GB hard drive rather than the innovative dual-storage system of the older S101. However, apparently there may be versions of the S121 with 2GB of RAM and Windows Vista Home, and the hard drive can be upgraded to a 512GB SSD model! Draft-N Wi-Fi and Bluetooth 2.1 are of course on hand for wireless duties.
Though apparently a four-cell battery will be available, our S121 came with a high-capacity six-cell slim slab battery rated at 7,200mAh/52Wh. Not quite up to the 1000HE's amazing 8,700mAh, but thanks to the usable screen at minimum brightness and slower Atom CPU using a maximum 1.1W rather than the 2.5W of more powerful models, we guess battery life will be comparable - especially when opting for the SSD drive. As is, a quick manual test with medium screen brightness and wireless turned on left us with around four hours and twenty minutes of use. Despite its high-capacity battery and a larger screen than most, the S121 still comes in at a very portable 1.5kg.
Overall, Asus has set quite the 12in netbook template for other manufacturers to aspire to. Its S121 looks even more desirable than the S101, is sturdy and a pleasure to use, and offers excellent battery life into the bargain. With no confirmed pricing it's difficult to know if the S121 will offer good value for money, but it's clear this luxury netbook will give the impression of expense.
If the S121 turns out to be truly capable of smooth high-definition video playback to match the screen's resolution, the S121 might be worth its asking price for the practically as well as stylistically minded, but with the Intel GN40 chipset or nVidia ION platform on their way, it might be worth holding back.