From my understanding, with the Smart Feather you can't just take off the Smart Cover anytime you wish to do so. The Smart Feather I think anchors the SC to the iPad, thus making it immovable (which is considered a plus by many, as sometimes the SCs tend to come off without wanting to do so). From what I've heard, if you didn't like that, the Belkin Snap Shield or (when it comes out) the SwitchEasy cover buddy might be more suited?
Anyone else can chime in as I don't have a feather but plan on buying one in the near future when the other colors come out.