There are a few YouTube videos proving my point. Here's one in particular. He mentions the cloudiness right in the beginning and you can easily see it. What's the point of buying a clear keyboard protector that turns hazy after a short time, it makes it hard to see the keys. That's what's unique about the iSkin, it's colored to match the keys, plus the etchings for the backlighted keyboard.
http://www.youtube.com/watch?v=NvOkarh5SrU