At first glance, Smart Back Cover is very similar to Incipio’s Feather, XtremeMac’s Microshield, or other snap-on plastic shells we’ve reviewed. It’s nice and thin, attaching snugly to the back of the iPad 2 and covering the front aluminum edge. The bottom side of the iPad 2 is well protected, with a clean-looking scoop to expose the Dock Connector and a 4x13 grille of squares over the speaker that keeps the metal protected…