I have the moshi and have been using it for a year now. Here are my thoughts on it
Pros:
Incredibly thin
Doesn't make a difference to the typing feel
No heat issues
Protects keyboard from crumbs, spilled drinks and such
Cons:
Pricey
Turns yellow
Fragile, Moshi recommends to never fold the product
Cannot be washed
Leaves an imprint on the laptop screen when you close the lid
Overall, it is definitely a great way to protect your keyboard. However, the shortcomings have convinced me to ditch it. It doesn't allow your laptop to fully close even with how thin it is. Also, when you open the lid you'll see the keyboard keys imprinted on your screen. The moshi will catch all the dirt and oil from your fingers and hands and can't really be washed. I used it on my Macbook Pro for about a month or so before finally removing it, now I use it on my bluetooth wireless keyboard