The BSE skin is an invisible protective shield that is applied on the surface of the phone. It should not be mistaken for a case skin
which is real case which surrounds the sides and back of the phone.
Using a BSE skin will not obstruct anything. However, using a skin case will keep you from accessing the battery compartment.
The BSE skin can be only applied once. Once it is set it's on forever, until you decide to remove and throw it away. So it's important to fix all imperfections before you let it set. However, a skin case can be used and removed over and over again.
The BSE skin will give the Pearl a glossy finish. It isn't noticeable at all unless you look for it. Also, the skin gives the Pearl a more grippy finish. The skin will protect the surface from scratches and the like. I haven't experienced any scratching so far so that's good. You can check out videos on how well it does its job on the ShieldZone website here
. The ShieldZone and BestSkinsEver skins are basically the same product with differences in coverage and price.
Hope this helps.