One of the highlights of the S121 is definitely the keyboard, and I would go so far as to say it's the best I have used on an Asus netbook. Rather than the cramped layout of earlier Eee PCs, the average chicklet-style keyboard of the recently-reviewed 1000HE or even the medium-sized effort on the S101, the S121's keyboard is full-size and similar in look and feel to the excellent implementation of the HP's Compaq Mini 700.
In fact, the low-profile keys on the 12in S121 are exactly the same size as those on the 8.9in Mini 700, which really is a testament to HP's engineering prowess. However, the S121's keys have slightly better separation and the extra space has allowed Asus to fit a row of dedicated Page Up, Down, Home and End keys. Feedback is a tad on the shallow side and the keyboard doesn't feel quite as reassuringly solid as the rest of the machine, but aside from this it's a superb example which is very pleasant to type on.
Layout is excellent, with the Ctrl key to the outside of Fn and the right-Shift key to the inside of the up-cursor key. Our sample of the S121 had a US-style smaller Enter key with the '\' symbol above it, but we assume that as with the S101 there will be a dedicated UK layout when it comes to market here.
The touchpad and wrist-rest also deserve special mention. As you can see from the pictures, the keyboard's surround is metal, as is a strip towards the front edge of the S121 containing the indicator icons and metal touchpad button. Between these, the actual palm-rest area is real leather, matching the lid perfectly with its dark brown finish with golden 'glitter'. It also offers great user comfort.
The large touchpad is brown brushed metal (with golden glitter, naturally). It's perfectly responsive and a joy to use. Unfortunately the same cannot be said about the silver metal buttons just below it. Made of a single bar, the left 'button' is easy to use, lying comfortably under the thumb and with a positive click. The right one, however, is not only far stiffer, but requires you to stretch quite a bit to reach it.
Above the screen is the same 1.3-megapixel webcam found on most netbooks these days. Getting to the screen itself, it's actually rather good. The 12in LED backlit screen itself is a major upgrade from what's found on most netbooks, sporting a WXGA (1,280 x 800) resolution. Since the screen supports a high definition resolution, running 720p HD content on the S121 has been addressed by employing Intel's System Controller Hub US15W (with Intel's GMA500 graphics media accelerator). The GMA500 chip has been designed to support high-definition decoding as it has hardware video decode acceleration and should therefore take the load off the weaker Atom Z520 CPU. However, whether or not the video playboack is 'smooth' remains to be seen.
As far as image quality goes, though the display couldn't quite distinguish between extreme shades in our greyscale test it's certainly acceptable performance for a netbook screen. In the positives column, there is no sign of backlight bleed or banding, text is razor-sharp and viewing angles are very strong. Colours are punchy and vibrant due to the screen's reflective coating, though this does mean you get that distracting mirror effect. It's also worth noting that unlike many, the screen is perfectly usable at its minimum brightness, portending good things for the S121's battery life.