I've tried BSE and couple of other skins, but they were all nearly impossible to apply cleanly without air pockets/bubbles forming. Also, you need a really dust-free environment (which I don't have since I have forced-air heating system) or they'll all show up on the skin as you install them. For me, it was not worth all the hassles and efforts.
I'll always take the ease of physical case, and deal with the added bulk.