The first thing one notices about them is that the two models are quite different. The S1 model is the most iPad-like in that it is a single screen with a black surround. The S2 model has two screens (hence ‘S2′ I suppose).
Sony says that the S1 model is “optimized for rich media entertainment”, whilst the S2 is “ideal for mobile communication and entertainment.” My first thought on this is that by having two separate devices Sony is already dividing its market. Apple has stuck with one basic device with just the memory and Wi-Fi/3G capability to distinguish the models from one another in the range. I can see this approach being a problem for Sony if it really does want to be No. 2 in the Tablet market.
As far as the differences between the devices go, obviously the screens are the main difference. The S1 has a 9.4-inch compared to the S2′s dual 5.5-inch screens. The S2 folds in the middle as it is hinged between the screens, in a clamshell design. It has been described as looking like a “squashed burrito” when closed! The S1 has a wedge-shaped design, which Sony claims makes it more comfortable to hold for extended periods.
More detailed specifications have yet to be confirmed. indeed, Sony says on its site (see image above) that the design is “subject to change”.
Whether we are truly looking at a worthy competitor to the iPad remains to be seen. Sony has certainly got a worthy track-record when it comes to designing cool looking laptops but it remains to be seen whether it can bring the same design capability to bear on the tablet market.