I have it. It has a nice grip and is hardly there from a standpoint that it adds very little bulk to the phone. But it does nothing more than protect the back and add some "grip". It does not cover the bezel nor come up high enough to lay the phone on its face. I like it overall, but I have also just ordered a Speck Candyshell for more protection - and I'll swap back and forth.
To add something that has bugged me a little about the Feather - my black one always feels like the back has little sand particles on it. It has a nice matte finish that gives grip, but it also feels a little "gritty" no matter how much I wipe it off. Anyone else "feel" this?