this cover works well, but beware - if you use hand lotion, the plastic will stain. i'm looking for a replacement cover now, as mine is very dirty looking after a year's worth of use. tried scrubbing, the properties of the oils in the lotion has reacted with the plastic and is permanently yellowed in certain areas. my non-lotion using coworkers moshis are fairly mark-free though.
I bought this because the white keys on the keyboard get very dirty with any regular use. While it does what it's supposed to do I don't like it. First, while it protects the keyboard, it also gets dirty and I couldn't clean it very well. And second, it makes the typing quite a bit softer, which to me causes more mistakes. I like to hit the keys a little hard and like the feel of the keys as they are on the keyboard. I don't like the soft feel of it at all.