The differences between the two models are minor. Like the other non-clear covers here, the Checkerboard's solid keytops block keyboard backlighting; the Clear lets you see the keyboard's actual keys. Also, I found that the Clear was slightly more flexible, likely because of the lack of labels on each key, compared to the Checkerboard. The downside of this flexibility is that the Clear's silicone occasionally got stuck underneath the edge of the space bar, preventing it from recognizing key presses. This didn't happen frequently, but often enough that I noticed.

Moshi Clearguard

Moshi's $25 is the only cover I tested not made of silicone; instead, it's made of thermoplastic urethane that's 0.1mm thick--by far the thinnest keyboard cover here. This material and its thinness provide two immediately obvious benefits. First, the Clearguard is almost completely clear; when placed on a MacBook's keyboard, you can barely even see the cover, and if you've got a backlit keyboard, that lighting shines through at full brightness. Second, although you do notice the Clearguard while typing--it gives the key surfaces a slightly tacky feel--the overall feel of typing is affected less by the Clearguard than by any other keyboard cover I've used. Compared to a bare keyboard, it takes approximately the same amount of pressure to activate each key, and the tactile response you get is nearly unchanged.

Although I haven't used the Clearguard long enough to determine how its material will hold up, over time, compared to a thicker silicone cover, after a month or so of use it's become my keyboard cover of choice.

VisiKey VisiSkin