"Aluminum Tough" - Asus refers to the aluminum applications on the S56CM's casing with this marketing term. Unlike the Zenbooks, a full-aluminum casing or even a unibody build (UX31A) is not used here. Instead single parts of the casing consist of the elegant metal.

The black display lid that suggests a high robustness and quality with its pleasant and cool feel the first time we touch it is also among these parts. The base unit is also clad in elegant brushed aluminum, but in a stylish silver rather than black. All this quickly creates a positive and surprisingly high-end first impression.

The casing of Asus' S56CM cannot completely confirm the preliminary impression at second glance. The build quality is absolutely satisfactory for a consumer device from this price range. However, just opening the ultrabook seems a bit too easy and consequently the lid opens by half a centimeter when the device is placed on its rear because the lid does not close securely enough to the base unit. Thus, the user should take care particularly when carrying the ultrabook around because the sensitive screen is not protected by a tighter closure.

Beyond that, the display hinges keep the lid firmly enough in position, but it nevertheless rocks visibly on even slightly vibrating surfaces. We would appreciate considerably tighter hinges with a firmer hold here.

In terms of torsional stiffness, neither the display lid nor the base unit yields to warping, not even under selective pressure. The casing can only be dented marginally when stronger pressure is applied by a finger on the right, above the built-in DVD burner and on the keyboard. The keyboard flexing, which is a known problem especially from Asus' UX32VD, hardly exists in this model and does not deter a normal use of the keyboard in any way.

The mentioned DVD drive is a positive unique selling point in a slim ultrabook, but the very fragile and wobbly implementation is disagreeable. The user should handle it very carefully in order to prevent damage. The drive also has too much play which causes unsightly scratches on the drive's upper edge.

Overall, the Asus S56CM can be said to have a more than satisfactory casing quality. However, the potential buyer should keep in mind that the ultrabook does not go beyond the standard quality of a low-budget consumer device despite the aluminum components.