
Following up on my review of RadTech's ScreenSavrz, here is my review of the Sleevz sleeve for the 13" Air.
From RadTech's website:
Extremely lightweight, flexible and durable like RadTech's popular ScreenSavrz. Sleevz offer substantial protection without adding to your load. Average weight is just 36 grams and Sleevz fold up small enough to easily fit in your pack, purse or pocket. Protects the exterior finish of the notebook from your larger case's zippers, rough linings and hardware - or anything else which might cause damage. Makes a great, hassle-free tote when you just need to take the 'Book. And all RadTech Sleevz are TSA Checkpoint Friendly.

As the image shows, when it's not filled with the Air, the case looks as if it won't fill, but as the image at the top shows, it is a perfect fit overall. As it is thin, you can easily and compactly fold the sleeve up for storage when you're not using it, and personally, I do like the color.
However, I have to admit that the term "substantial protection" leaves a bit to be desired. I sort of expected this when I saw other reviews of the sleeve here in MacRumors and elsewhere, but the degree of protection the sleeve gives is against scratches, and that's about it. The sleeve has no padding whatsoever, so I wouldn't recommend this sleeve if you're only going to carry the Air around and you consider yourself to be clumsy.
If you take the padding aspect out, then the sleeve does as advertised (though I can't confirm the TSA part since I don't live in the US). It definitely keeps other things in the bag away from scratches and dings.
I would rate the Sleevz as "recommend with reservations."